QuickLinks -- Click here to rapidly navigate through this document


Filed pursuant to 424(b)(3)
Registration No. 333-200594


BLACK CREEK INDUSTRIAL REIT IV INC.
SUPPLEMENT NO. 5 DATED NOVEMBER 2, 2017
TO THE PROSPECTUS DATED JULY 3, 2017

        This prospectus supplement ("Supplement") is part of and should be read in conjunction with the prospectus of Black Creek Industrial REIT IV Inc., dated July 3, 2017 (the "Prospectus"), as supplemented by Supplement No. 1, dated August 9, 2017, Supplement No. 2, dated August 28, 2017, Supplement No. 3, dated September 13, 2017 and Supplement No. 4, dated September 21, 2017. Unless otherwise defined herein, capitalized terms used in this Supplement shall have the same meanings as in the Prospectus.

        The purpose of this Supplement is as follows:

A.    Update regarding the share redemption programs

        The board of directors has determined that it is advisable and in our best interests to amend and restate our share redemption program applicable to Class I and Class W shares to be applicable to all shares of our common stock, regardless of share class. Accordingly, we have terminated our share redemption program applicable to Class T shares. In addition, the amended and restated share redemption program provides that the 5% Early Redemption Deduction is applicable to all shares of our common stock that have been outstanding for less than one year and provides for a 2.5% Early Redemption Deduction applicable to Class T shares that have been outstanding for at least one year but less than two years. There were no other changes made to our share redemption program as part of its amendment and restatement.

        As we have adopted one share redemption program applicable to all shares of our common stock, any reference in the Prospectus to our share redemption program applicable to Class T shares or our share redemption program applicable to Class W and Class I shares is hereby superseded. Further, any reference in the Prospectus to a comparison between the share redemption program applicable to Class T shares and the share redemption program applicable to Class W and Class I shares is hereby superseded. Further, any reference in the Prospectus to "share redemption programs" is hereby superseded and replaced with a reference to a singular "share redemption program."

        In addition, the following sections of the Prospectus are amended as follows:

        1.     The section titled "Prospectus Summary—Share Redemption Programs" is hereby renamed "Prospectus Summary—Share Redemption Program" and the disclosure in that section, beginning on page 31 of the Prospectus is superseded and replaced with:

Share Redemption Program

        We expect that there will be no regular secondary trading market for shares of our common stock. While you should view your investment as long term with limited liquidity, we have adopted a share redemption program applicable to all shares of our common stock, whereby stockholders who have purchased shares from us or received their shares through a non-cash transaction, not in the secondary market, may receive the benefit of limited liquidity by presenting for redemption to us all or any

S-1


portion of those shares in accordance with the procedures and subject to certain conditions and limitations described in "Description of Capital Stock—Share Redemption Program." To the extent our board of directors determines that we have sufficient available cash for redemptions, we initially intend to redeem shares under our share redemption program on a monthly basis; however, our board of directors may determine from time to time to adjust the timing of redemptions or suspend, terminate or otherwise modify our share redemption program.

        While stockholders may request on a monthly basis that we redeem all or any portion of their shares pursuant to our share redemption program, we are not obligated to redeem any shares and may choose to redeem only some, or even none, of the shares that have been requested to be redeemed in any particular month, in our discretion. In addition, our ability to fulfill redemption requests is subject to a number of limitations. As a result, share redemptions may not be available each month. Under our share redemption program, to the extent we determine to redeem shares in any particular month, we will only redeem shares as of the last calendar day of that month (each such date, a "Redemption Date"). Redemptions will be made at the transaction price in effect on the Redemption Date (which, once we commence monthly valuations, will generally be equal to our most recently disclosed monthly NAV per share, but will initially be equal to $10.00 per share), except that shares that have not been outstanding for at least one year will be redeemed at 95% of the transaction price and Class T shares that have been outstanding for at least one year but less than two years will be redeemed at 97.5% of the transaction price. Each of these deductions is referred to as an Early Redemption Deduction. An Early Redemption Deduction will not be applied to Class W shares and Class I shares that have been outstanding for at least one year and Class T shares that have been outstanding for at least two years. An Early Redemption Deduction may be waived in certain circumstances including: (i) in the case of redemption requests arising from the death or qualified disability of the holder; (ii) in the event that a stockholder's shares are redeemed because the stockholder has failed to maintain the $2,000 minimum account balance; or (iii) with respect to shares purchased through our distribution reinvestment plan or received from us as a stock dividend. To have your shares redeemed, your redemption request and required documentation must be received in good order by 4:00 p.m. (Eastern time) on the second to last business day of the applicable month. Settlements of share redemptions will be made within three business days of the Redemption Date. An investor may withdraw its redemption request by notifying the transfer agent before 4:00 p.m. (Eastern time) on the last business day of the applicable month.

        Under our share redemption program, we may redeem during any calendar month shares whose aggregate value (based on the price at which the shares are redeemed) is 2% of our aggregate NAV as of the last calendar day of the previous quarter and during any calendar quarter whose aggregate value (based on the price at which the shares are redeemed) is up to 5% of our aggregate NAV as of the last calendar day of the prior calendar quarter. During a given quarter, if in each of the first two months of such quarter the 2% redemption limit is reached and stockholders' redemptions are reduced pro rata for such months, then in the third and final month of that quarter, the applicable limit for such month will likely be less than 2% of our aggregate NAV as of the last calendar day of the previous month because the redemptions for that month, combined with the redemptions in the previous two months, cannot exceed 5% of our aggregate NAV as of the last calendar day of the prior calendar quarter.

        Although the vast majority of our assets consist of properties that cannot generally be readily liquidated on short notice without impacting our ability to realize full value upon their disposition, we intend to maintain a number of sources of liquidity including (i) cash equivalents (e.g. money market funds), other short-term investments, U.S. government securities, agency securities and liquid real estate-related securities and (ii) one or more borrowing facilities. We may fund redemptions from any available source of funds, including operating cash flows, borrowings, proceeds from this offering and/or sales of our assets.

        Should redemption requests, in our judgment, place an undue burden on our liquidity, adversely affect our operations or risk having an adverse impact on the company as a whole, or should we

S-2


otherwise determine that investing our liquid assets in real properties or other illiquid investments rather than redeeming our shares is in the best interests of the company as a whole, then we may choose to redeem fewer shares than have been requested to be redeemed, or none at all. In the event that we determine to redeem some but not all of the shares submitted for redemption during any month for any of the foregoing reasons, shares submitted for redemption during such month will be redeemed on a pro rata basis. All unsatisfied redemption requests must be resubmitted after the start of the next month or quarter, or upon the recommencement of the share redemption program, as applicable. If the transaction price for the applicable month is not made available by the tenth business day prior to the last business day of the month (or is changed after such date), then no redemption requests will be accepted for such month and stockholders who wish to have their shares redeemed the following month must resubmit their redemption requests. See "Description of Capital Stock—Share Redemption Program."

        2.     The following supersedes and replaces the response to the question, "Can I Request That My Shares Be Redeemed?" in the section titled "Questions and Answers About This Offering" beginning on page 49 of the Prospectus:

Q:    CAN I REQUEST THAT MY SHARES BE REDEEMED?

        A:    Yes. We expect that there will be no regular secondary trading market for shares of our common stock. While you should view your investment as long term with limited liquidity, we have adopted a share redemption program applicable to all shares of our common stock, whereby stockholders who have purchased shares from us or received their shares through a non-cash transaction, not in the secondary market, may receive the benefit of limited liquidity by presenting for redemption to us all or any portion of those shares in accordance with the procedures and subject to certain conditions and limitations described in "Description of Capital Stock—Share Redemption Program." To the extent our board of directors determines that we have sufficient available cash for redemptions, we initially intend to redeem shares under our share redemption program on a monthly basis; however, our board of directors may determine from time to time to adjust the timing of redemptions or suspend, terminate or otherwise modify our share redemption program.

        While stockholders may request on a monthly basis that we redeem all or any portion of their shares pursuant to our share redemption program, we are not obligated to redeem any shares and may choose to redeem only some, or even none, of the shares that have been requested to be redeemed in any particular month, in our discretion. In addition, our ability to fulfill redemption requests is subject to a number of limitations. As a result, share redemptions may not be available each month. Under our share redemption program, to the extent we determine to redeem shares in any particular month, we will only redeem shares as of the last calendar day of that month (each such date, a "Redemption Date"). Redemptions will be made at the transaction price in effect on the Redemption Date (which, once we commence monthly valuations, will generally be equal to our most recently disclosed monthly NAV per share, but will initially be equal to $10.00 per share), except that shares that have not been outstanding for at least one year will be redeemed at 95% of the transaction price and Class T shares that have been outstanding for at least one year but less than two years will be redeemed at 97.5% of the transaction price. Each of these deductions is referred to as an Early Redemption Deduction. An Early Redemption Deduction will not be applied to Class W shares and Class I shares that have been outstanding for at least one year and Class T shares that have been outstanding for at least two years. An Early Redemption Deduction may be waived in certain circumstances including: (i) in the case of redemption requests arising from the death or qualified disability of the holder; (ii) in the event that a stockholder's shares are redeemed because the stockholder has failed to maintain the $2,000 minimum account balance; or (iii) with respect to shares purchased through our distribution reinvestment plan or received from us as a stock dividend. To have your shares redeemed, your redemption request and required documentation must be received in good order by 4:00 p.m. (Eastern time) on the second to

S-3


last business day of the applicable month. Settlements of share redemptions will be made within three business days of the Redemption Date. An investor may withdraw its redemption request by notifying the transfer agent before 4:00 p.m. (Eastern time) on the last business day of the applicable month.

        Under our share redemption program, we may redeem during any calendar month shares whose aggregate value (based on the price at which the shares are redeemed) is 2% of our aggregate NAV as of the last calendar day of the previous quarter and during any calendar quarter whose aggregate value (based on the price at which the shares are redeemed) is up to 5% of our aggregate NAV as of the last calendar day of the prior calendar quarter. During a given quarter, if in each of the first two months of such quarter the 2% redemption limit is reached and stockholders' redemptions are reduced pro rata for such months, then in the third and final month of that quarter, the applicable limit for such month will likely be less than 2% of our aggregate NAV as of the last calendar day of the previous month because the redemptions for that month, combined with the redemptions in the previous two months, cannot exceed 5% of our aggregate NAV as of the last calendar day of the prior calendar quarter.

        Although the vast majority of our assets consist of properties that cannot generally be readily liquidated on short notice without impacting our ability to realize full value upon their disposition, we intend to maintain a number of sources of liquidity including (i) cash equivalents (e.g. money market funds), other short-term investments, U.S. government securities, agency securities and liquid real estate-related securities and (ii) one or more borrowing facilities. We may fund redemptions from any available source of funds, including operating cash flows, borrowings, proceeds from this offering and/or sales of our assets.

        Should redemption requests, in our judgment, place an undue burden on our liquidity, adversely affect our operations or risk having an adverse impact on the company as a whole, or should we otherwise determine that investing our liquid assets in real properties or other illiquid investments rather than redeeming our shares is in the best interests of the company as a whole, then we may choose to redeem fewer shares than have been requested to be redeemed, or none at all. In the event that we determine to redeem some but not all of the shares submitted for redemption during any month for any of the foregoing reasons, shares submitted for redemption during such month will be redeemed on a pro rata basis. All unsatisfied redemption requests must be resubmitted after the start of the next month or quarter, or upon the recommencement of the share redemption program, as applicable. If the transaction price for the applicable month is not made available by the tenth business day prior to the last business day of the month (or is changed after such date), then no redemption requests will be accepted for such month and stockholders who wish to have their shares redeemed the following month must resubmit their redemption requests. See "Description of Capital Stock—Share Redemption Program."

        3.     The following risk factor supersedes and replaces the last two risk factors on page 53 of the Prospectus in the section titled "Risk Factors—Risk Related To Investing In This Offering":

         There is no public trading market for the shares of our common stock and we do not anticipate that there will be a public trading market for our shares; therefore, your ability to dispose of your shares will likely be limited to redemption by us. If you do sell your shares to us, you may receive less than the price you paid.

        There is no public market for the shares of our common stock and we currently have no obligation or plans to apply for listing on any public securities market. Therefore, redemption of the shares of our common stock by us will likely be the only way for you to dispose of your shares. We will redeem shares at a price equal to the transaction price on the last calendar day of the applicable month (which initially is equal to $10.00 per share, but will generally be equal to our most recently disclosed monthly NAV per share once we commence monthly valuations), and not based on the price at which you initially purchased your shares. We may redeem your shares if you fail to maintain a minimum balance of $2,000 of shares, even if your failure to meet the minimum balance is caused solely by a decline in our NAV. Since Class T shares are sold at the transaction price plus applicable selling commissions and

S-4


dealer manager fees, holders of Class T shares may receive less than the price they paid for their shares upon redemption by us. Subject to limited exceptions, holders of our common stock that have not held their shares for at least one year will be eligible for redemption at 95% of the transaction price on the redemption date and holders of Class T shares that have held their shares for at least one year but less than two years will be eligible for redemption at 97.5% of the transaction price on the redemption date, which will inure indirectly to the benefit of our remaining stockholders. As a result of this and the fact that our NAV will fluctuate, holders of our common stock may receive less than the price they paid for their shares upon redemption by us. See "Description of Capital Stock—Share Redemption Program."

         Our ability to redeem your shares may be limited. In addition, our board of directors may modify, suspend or terminate our share redemption program at any time.

        Our share redemption program contains significant restrictions and limitations. For example, only stockholders who purchase their shares directly from us or who received their shares through a non-cash transaction, not in the secondary market, are eligible to participate and if holders of our common stock do not hold their shares for a minimum of one year, then they will only be eligible for redemption at 95% of the transaction price on the redemption date. Further, if holders of Class T shares have held their shares for at least one year but less than two years, they will only be eligible for redemption at 97.5% of the transaction price on the redemption date.

        We may redeem fewer shares than have been requested in any particular month to be redeemed under our share redemption program, or none at all, in our discretion at any time. We may redeem fewer shares due to the total amount of shares requested for redemption being in excess of the limits and/or caps applicable to our redemption program, the lack of readily available funds because of adverse market conditions beyond our control, the need to maintain liquidity for our operations or because we have determined that investing in real property or other illiquid investments is a better use of our capital than redeeming our shares.

        The vast majority of our assets will consist of properties which cannot generally be readily liquidated on short notice without impacting our ability to realize full value upon their disposition. Therefore, we may not always have a sufficient amount of cash to immediately satisfy redemption requests. Further, we may invest in real estate-related securities and other securities with the primary goal of maintaining liquidity in support of our share redemption program. Any such investments may result in lower returns than an investment in real estate assets, which could adversely impact our ability to pay distributions and your overall return. In addition, our board of directors may modify, suspend or terminate our share redemption program at any time in its sole discretion. As a result, your ability to have your shares redeemed by us may be limited, our shares should be considered as having only limited liquidity and at times may be illiquid. See "Description of Capital Stock—Share Redemption Program" for more information, including a description of the different limits and caps applicable to our share redemption program.

        4.     The section titled "Description of Capital Stock—Share Redemption Programs" is hereby renamed "Description of Capital Stock—Share Redemption Program" and the disclosure in that section, beginning on page 214 of the Prospectus is superseded and replaced with:

        We expect that there will be no regular secondary trading market for shares of our common stock. While you should view your investment as long term with limited liquidity, we have adopted a share redemption program applicable to all shares of our common stock, whereby stockholders who have purchased shares from us or received their shares through a non-cash transaction, not in the secondary market, may receive the benefit of limited liquidity by presenting for redemption to us all or any portion of those shares in accordance with the procedures and subject to certain conditions and limitations described below. To the extent our board of directors determines that we have sufficient available cash for redemptions, we initially intend to redeem shares under our share redemption

S-5


program on a monthly basis; however, our board of directors may determine from time to time to adjust the timing of redemptions or suspend, terminate or otherwise modify our share redemption program as described below.

        Due to the illiquid nature of investments in real property, we may not have sufficient liquid resources to fund redemption requests. In addition, we have established limitations on the amount of funds we may use for redemptions and the amount of shares that may be redeemed. See "—Redemption Limitations" below.

        A stockholder's request for redemption in accordance with any of the special treatment described below in the event of the death or qualifying disability of a stockholder must be submitted within 18 months of the death of the stockholder or the initial determination of the stockholder's disability (which we define as such term is defined in Section 72(m)(7) of the Code), as further described below.

        There is no fee in connection with a redemption of shares of our common stock.

        You may request that we redeem shares of our common stock through your financial advisor or directly with our transfer agent. We will generally adhere to the following procedures relating to the redemption of shares of our common stock:

S-6


For regular mail:   For overnight deliveries:

DST Systems, Inc.
PO Box 219079
Kansas City, Missouri 64121-9079

 

DST Systems, Inc.
430 West 7th Street, Suite 219079
Kansas City, Missouri 64105

Toll Free Number: (888) 310-9352

        Corporate investors and other non-individual entities must have an appropriate certification on file authorizing redemptions. A signature guarantee may be required.

S-7


        In the event that any stockholder fails to maintain the minimum balance of $2,000 of shares of our common stock, we may redeem all of the shares held by that stockholder at the redemption price in effect on the date we determine that the stockholder has failed to meet the minimum balance, less any Early Redemption Deduction with respect to our share redemption program. Minimum account redemptions will apply even in the event that the failure to meet the minimum balance is caused solely by a decline in our NAV. Minimum account redemptions are subject to an Early Redemption Deduction.

        We may redeem fewer shares than have been requested to be redeemed in any particular month, or none at all, in our discretion at any time, including due to the total amount of shares requested for redemption being in excess of the limits described below, the lack of readily available funds because of market conditions, the need to maintain liquidity for operations or because our board of directors has determined that investing in real property or other illiquid investments is a better use of our capital than redeeming our shares. In the event that we determine to redeem some but not all of the shares submitted for redemption during any month for any of the foregoing reasons, shares submitted for redemption during such month will be redeemed on a pro rata basis. The portion of any unfulfilled redemption requests must be resubmitted after the start of the next month or quarter, or upon the recommencement of the share redemption program, as applicable. Any determination to redeem fewer shares than have been requested to be redeemed may be made immediately prior to the applicable Redemption Date, and will be disclosed subsequently to prospective investors and stockholders in periodic prospectus supplements and/or current or periodic reports filed by us, or more frequently as required by applicable securities laws. In addition, any determination to redeem fewer shares than have been requested to be redeemed under our share redemption program will not affect any determinations that may be made by our board of directors regarding requests by holders of OP Units for redemption of their OP Units pursuant to the Operating Partnership Agreement. Set forth below is a description of the limitations on redemptions pursuant to our share redemption program.

        Under our share redemption program, we may redeem during any calendar month shares whose aggregate value (based on the price at which the shares are redeemed) is 2% of our aggregate NAV as of the last calendar day of the previous quarter and during any calendar quarter whose aggregate value (based on the price at which the shares are redeemed) is up to 5% of our aggregate NAV as of the last calendar day of the prior calendar quarter. During a given quarter, if in each of the first two months of such quarter the 2% redemption limit is reached and stockholders' redemptions are reduced pro rata for such months, then in the third and final month of that quarter, the applicable limit for such month will likely be less than 2% of our aggregate NAV as of the last calendar day of the previous month because the redemptions for that month, combined with the redemptions in the previous two months, cannot exceed 5% of our aggregate NAV as of the last calendar day of the prior calendar quarter.

S-8


        We may, in the Advisor's discretion, after taking the interests of our company as a whole and the interests of our remaining stockholders into consideration, use proceeds from any available sources at our disposal to satisfy redemption requests, subject to the limitation on the amount of funds we may use described above under "—Redemption Limitations." Potential sources of funding for redemptions pursuant to our share redemption program include, but are not limited to, cash on hand, cash available from borrowings, cash from the sale of shares of our common stock and cash from liquidations of investments, to the extent that such funds are not otherwise dedicated to a particular use, such as working capital, cash distributions to stockholders, purchases of real property, debt-related or other investments or redemption of OP Units.

        Upon commencing operations, our assets may consist of properties that cannot generally be readily liquidated on short notice without impacting our ability to realize full value upon their disposition, we intend to maintain a number of sources of liquidity including (i) cash equivalents (e.g. money market funds), other short-term investments, U.S. government securities, agency securities and liquid real estate-related securities and (ii) one or more borrowing facilities. We may fund redemptions from any available source of funds, including operating cash flows, borrowings, proceeds from this offering and/or sales of our assets.

        As described above, should redemption requests, in our judgment, place an undue burden on our liquidity, adversely affect our operations or risk having an adverse impact on the company as a whole, or should we otherwise determine that investing our liquid assets in real properties or other illiquid investments rather than repurchasing our shares is in the best interests of the company as a whole, we may choose to redeem fewer shares in any particular month than have been requested to be redeemed, or none at all. Further, our board of directors may modify, suspend or terminate our share redemption program if it deems such action to be in our best interest and the best interest of our stockholders. Material modifications to the share redemption program, including, without limitation, any amendment to the limitations on redemptions, as well as the suspension or termination of the share redemption program will be promptly disclosed to stockholders in a prospectus supplement (or post-effective amendment if required by the Securities Act) or current or periodic report filed by us. Material modifications will also be disclosed on our website. In addition, we may determine to suspend the share redemption program due to regulatory changes, changes in law or if we become aware of undisclosed material information that we believe should be publicly disclosed before shares are redeemed. Once the share redemption program has been suspended, our board of directors must affirmatively authorize the recommencement of the program before stockholder requests will be considered again. Our share redemption program will be immediately terminated if our shares of common stock are listed on a national securities exchange or if a secondary market is otherwise established. Any modification, suspension or termination of our share redemption program will not affect the rights of holders of OP Units to cause us to redeem their OP Units pursuant to the Operating Partnership Agreement.

        There is no minimum holding period under our share redemption program and holders of shares of our common stock can request that we redeem their shares at any time. However, subject to limited exceptions, shares of our common stock that have not been outstanding for at least one year will be redeemed at 95% of the transaction price and Class T shares that have been outstanding for at least one year but less than two years will be redeemed at 97.5% of the transaction price. Each of these deductions is referred to as an Early Redemption Deduction. An Early Redemption Deduction will not be applied to Class W shares and Class I shares that have been outstanding for at least one year and Class T shares that have been outstanding for at least two years.

S-9


        For purposes of determining whether an Early Redemption Deduction is applicable, holders of Class T shares that are converted to Class I shares pursuant to the terms of our charter shall be deemed to have owned their Class I shares as of the date they were issued the applicable Class T shares that were converted into such Class I shares. In addition, holders of OP Units who exchange their OP Units for shares of our common stock shall be deemed to have owned their shares as of the date they were issued their OP Units that were exchanged for such shares.

        Any Early Redemption Deduction will inure indirectly to the benefit of our remaining stockholders and is intended to offset the trading costs, market impact and other costs associated with short-term trading in our common stock. We may, from time to time, waive an Early Redemption Deduction in the following circumstances:

        In addition, an Early Redemption Deduction may not apply to transactions initiated by the trustee or advisor to a donor-advised charitable gift fund, collective trust fund, common trust fund, fund of fund(s) or other institutional accounts, strategy funds or programs if we determine, in our sole discretion, such account, fund or program has an investment strategy or policy that is reasonably likely to control short-term trading. Further, shares of our common stock may be sold to certain employer sponsored plans, bank or trust company accounts and accounts of certain financial institutions or intermediaries for which we may not apply an Early Redemption Deduction to the underlying stockholders, often because of administrative or systems limitations. An Early Redemption Deduction also will not apply to shares taken by our Advisor or Sponsor in lieu of fees or expense reimbursements under the Advisory Agreement or Operating Partnership Agreement, though such shares shall not be eligible for redemption under the program until six months after their issue date.

        As set forth above, we may waive certain of the terms and requirements of our share redemption program in respect of the redemption of shares resulting from the death of a stockholder who is a natural person, subject to the conditions and limitations described above, including shares held by such stockholder through a revocable grantor trust or an IRA or other retirement or profit-sharing plan, after receiving written notice from the estate of the stockholder, the recipient of the shares through bequest or inheritance, or, in the case of a revocable grantor trust, the trustee of such trust, who shall have the sole ability to request redemption on behalf of the trust. We must receive the written redemption request within 18 months after the death of the stockholder in order for the requesting party to rely on any of the special treatment described above that may be afforded in the event of the death of a stockholder. Such a written request must be accompanied by a certified copy of the official death certificate of the stockholder. If spouses are joint registered holders of shares, the request to have the shares redeemed may be made if either of the registered holders dies. If the stockholder is not a natural person, such as certain trusts or a partnership, corporation or other similar entity, the right of redemption upon death does not apply.

        Furthermore, as set forth above, we may waive certain of the terms and requirements of our share redemption program in respect of the redemption of shares held by a stockholder who is a natural person who is deemed to have a qualifying disability (as such term is defined in Section 72(m)(7) of the Code), subject to the conditions and limitations described above, including shares held by such stockholder through a revocable grantor trust, or an IRA or other retirement or profit-sharing plan,

S-10


after receiving written notice from such stockholder, provided that the condition causing the qualifying disability was not pre-existing on the date that the stockholder became a stockholder. We must receive the written redemption request within 18 months of the initial determination of the stockholder's disability in order for the stockholder to rely on any of the waivers described above that may be granted in the event of the disability of a stockholder. If spouses are joint registered holders of shares, the request to have the shares redeemed may be made if either of the registered holders acquires a qualifying disability. If the stockholder is not a natural person, such as certain trusts or a partnership, corporation or other similar entity, the right of redemption upon disability does not apply.

        When you make a request to have shares redeemed, you should note the following:

        IRS regulations require us to determine and disclose on Form 1099-B the adjusted cost basis for shares of our stock sold or redeemed. Although there are several available methods for determining the adjusted cost basis, unless you elect otherwise, which you may do by checking the appropriate box on the redemption form or calling our customer service number at (888) 310-9352, we will utilize the first-in-first-out method.

        The federal income tax consequences to you of participating in our share redemption program will vary depending upon your particular circumstances, and you are urged to consult your own tax advisor regarding the specific tax consequences to you of participation in our share redemption program.

        You will not relinquish your shares until we redeem them. The shares we redeem under our share redemption program will be cancelled and will have the status of authorized but unissued shares. We will not resell such shares to the public unless such sales are first registered with the SEC under the Securities Act and under appropriate state securities laws or are exempt under such laws.

        The transaction price approved by our board of directors in the future may be higher or lower than the most recently disclosed transaction price. The transaction price is not a representation, warranty or guarantee that (i) a stockholder would be able to realize such per share amount if such stockholder attempts to sell his or her shares; (ii) a stockholder would ultimately realize distributions per share equal to such per share amount upon our liquidation or sale; (iii) shares of our common stock would trade at such per share amount on a national securities exchange; or (iv) a third party would offer such per share amount in an arm's-length transaction to purchase all or substantially all of our shares of common stock.

S-11


        We and our transfer agent will not be responsible for the authenticity of mail or phone instructions or losses, if any, resulting from unauthorized stockholder transactions if they reasonably believe that such instructions were genuine. We and our transfer agent have established reasonable procedures to confirm that instructions are genuine including requiring the stockholder to provide certain specific identifying information on file and sending written confirmation to stockholders of record no later than five days following execution of the instruction. Stockholders, or their designated custodian or fiduciary, should carefully review such correspondence to ensure that the instructions were properly acted upon. If any discrepancies are noted, the stockholder, or its agent, should contact his, her or its financial advisor as well as our transfer agent in a timely manner, but in no event more than 60 days from receipt of such correspondence. Failure to notify such entities in a timely manner will relieve us, our transfer agent and the financial advisor of any liability with respect to the discrepancy.

B.    Update regarding eligibility to purchase Class I shares

        The following sentence supersedes and replaces the sentence regarding eligibility to purchase Class I shares in the section titled "Prospectus Summary—Class T Shares, Class W Shares and Class I Shares of Common Stock," the response to the question, "What are the Differences Among the Class T, Class W and Class I Shares of Common Stock Being Offered?" in the section titled "Questions and Answers About This Offering," in the section titled "Description of Capital Stock—Common Stock—Class I Shares," and in the section titled "Plan of Distribution—The Offering," on pages 3, 42, 205 and 263, respectively, of the Prospectus:

        Class I shares are available for purchase in this offering only (i) by institutional accounts as defined by FINRA Rule 4512(c), (ii) through bank-sponsored collective trusts and bank-sponsored common trusts, (iii) by retirement plans (including a trustee or custodian under any deferred compensation or pension or profit sharing plan or payroll deduction IRA established for the benefit of the employees of any company), foundations or endowments, (iv) through certain financial intermediaries that are not otherwise registered with or as a broker dealer and that direct clients to trade with a broker dealer that offers Class I shares, (v) by our executive officers and directors and their immediate family members, as well as officers and employees of the Advisor and the Dealer Manager and their immediate family members, officers and employees of the Advisor's product specialists or other affiliates of the Advisor and their immediate family members, our product specialists and their affiliates and, if approved by our board of directors, officers and employees of our joint venture partners and their immediate family members, consultants and other service providers, (vi) participating broker dealers, including their registered representatives and immediate family members, (vii) through bank trust departments or any other organization or person authorized to act as a fiduciary for its clients or customers and (viii) by any other categories of purchasers that we name in an amendment or supplement to this prospectus.

C.    Update to the Section of the Prospectus titled 'Questions and Answers About This Offering"

        The following paragraph supersedes and replaces the third paragraph in the response to the question, "What is the Liquidity Event History of Programs Sponsored by Your Advisor?" in the section titled "Questions and Answers About This Offering" on page 39 of the Prospectus:

        IIT sold shares of its common stock to investors from December 2009 through April 2012 at a share price of $10.00 per share in its initial public offering. IIT sold shares of its common stock pursuant to a follow-on offering from April 2012 through July 2013 at a share price of $10.40 per share. IIT announced an estimated NAV per share of its common stock of $11.04 as of December 31, 2014. On November 4, 2015, IIT completed its merger with and into Western Logistics II LLC, or "WL II," an affiliate of Global Logistic Properties Limited, or "GLP," in an all cash transaction valued

S-12


at approximately $4.55 billion, subject to certain transaction costs. In connection with the closing, stockholders of IIT were paid a cash distribution of $10.56 per share, as well as a distribution of units of beneficial interest in the liquidating trust described below, or the "DC Industrial Liquidating Trust." Academy Partners Ltd. Liability Company, or "Academy Partners", is the former owner of the names "Industrial Income Trust Inc.," "Industrial Income Trust" and "IIT," which we refer to collectively as the "Trademarks," and GLP (or its affiliate), which is unrelated to Academy Partners and its Dividend Capital Group LLC affiliates, is the present owner and source of services provided under the Trademarks. Concurrently with the closing of the merger, IIT transferred 11 properties that were under development or in the lease-up stage to DC Industrial Liquidating Trust, the beneficial interests in which were distributed to then-current IIT stockholders, with one unit being distributed for each share held. The DC Industrial Liquidating Trust units are illiquid. DC Industrial Liquidating Trust intends to sell such excluded properties. On August 3, 2017, the DC Industrial Liquidating Trust sold one of the excluded properties. On October 20, 2017, certain wholly owned subsidiaries of the DC Industrial Liquidating Trust entered into an Agreement with certain wholly owned subsidiaries of Black Creek Industrial Open End Fund OP LP to sell the 10 remaining real estate properties owned by the DC Industrial Liquidating Trust. Closing of the sale is expected to occur on or before December 11, 2017, subject to the satisfaction of certain customary closing conditions. The DC Industrial Liquidating Trust estimates that approximately $0.55 net per unit of beneficial interest in DC Industrial Liquidating Trust will be distributed to unitholders upon consummation of the sale of its 10 remaining real estate properties. There can be no assurance that the sale of the DC Industrial Liquidating Trust's remaining real estate properties will be consummated, or regarding the amount of cash that ultimately will be distributed to IIT's former stockholders in connection with the liquidation of the DC Industrial Liquidating Trust.

D.    Update to the section of the Prospectus titled "Management"

        1.     The following table supersedes and replaces the table in the section titled "Management—Directors and Executive Officers" on page 136 of the Prospectus:

        As of the date of this prospectus, our directors and executive officers, their ages and their positions and offices are as follows:

Name
  Age   Position

Evan H. Zucker

    52   Chairman and Director

Dwight L. Merriman III

    56   Managing Director, Chief Executive Officer and Director

Marshall M. Burton

    48   Independent Director

Stanley A. Moore

    78   Independent Director

John S. Hagestad

    70   Independent Director

Charles B. Duke

    59   Independent Director

Rajat Dhanda

    49   Managing Director, President

Thomas G. McGonagle

    57   Managing Director, Chief Financial Officer

Joshua J. Widoff

    47   Managing Director, Secretary and General Counsel

Scott W. Recknor

    50   Managing Director—Head of Asset Management

        2.     The following biographical information supplements, and should be read in conjunction with, the disclosure contained in the section titled "Management—Directors and Executive Officers" beginning on page 136 of the Prospectus:

         Scott W. Recknor , age 50, has served as our Managing Director—Head of Asset Management since April 2017, as our Managing Director—Asset Management from February 2016 to April 2017 and as our Senior Vice President—Asset Management from January 2013 to February 2016. Mr. Recknor also has served as DPF's Managing Director—Head of Asset Management Office and Industrial since July 2017. Mr. Recknor has served as IPT's Managing Director—Head of Asset Management since April

S-13


2017, as IPT's Managing Director—Asset Management from February 2016 to April 2017 and as IPT's Senior Vice President—Asset Management from January 2013 to February 2016. Mr. Recknor also served IIT's Senior Vice President—Asset Management from October 2010 until November 2015. From 2005 through October 2010, Mr. Recknor served as a Vice President for AMB Property Corporation (now ProLogis), a leading global owner, operator and developer of industrial real estate, where he was responsible for overseeing the leasing and operations of an approximate 20 million square foot industrial portfolio in the greater Los Angeles, Orange County and Inland Empire areas. From 2001 through 2004, Mr. Recknor served as a District Manager for RREEF where he oversaw all leasing, operations and reporting (to multiple separate accounts) for an approximate 10 million square foot industrial portfolio in the greater Los Angeles, Orange County and Inland Empire areas. Prior to RREEF, Mr. Recknor served as a Regional Real Estate Manager for the Goodyear Tire and Rubber Company (NASDAQ: GT) where he oversaw a retail and industrial portfolio located in six states (California, Hawaii, Nevada, Arizona, New Mexico and Texas). Mr. Recknor received his B.A. in Political Science from the University of California (Irvine). Mr. Recknor previously served on the Board of Directors for NAIOP (Southern California).

E.    Update to Appendix B

        The subscription agreement included as Appendix B to the Prospectus is hereby superseded and replaced with Appendix A to this supplement.

S-14



APPENDIX A: FORM OF SUBSCRIPTION AGREEMENT

GRAPHIC

A-1


GRAPHIC

A-2


GRAPHIC

A-3


GRAPHIC

A-4


GRAPHIC

A-5




QuickLinks

BLACK CREEK INDUSTRIAL REIT IV INC. SUPPLEMENT NO. 5 DATED NOVEMBER 2, 2017 TO THE PROSPECTUS DATED JULY 3, 2017
APPENDIX A: FORM OF SUBSCRIPTION AGREEMENT