UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 1-U

CURRENT REPORT

Pursuant to Regulation A of the Securities Act of 1933

September 1, 2026

Date of Report: (Date of earliest event reported)

MASTERWORKS VAULT 3, LLC

(Exact name of issuer as specified in its charter)

1 World Trade Center, 57th Floor, New York, NY 10007

(Full mailing address of principal executive offices)

(203) 518-5172

(Issuer’s telephone number, including area code)

www.masterworks.com

(Issuer’s website)

Series 325, Series 327, Series 330, Series 332, Series 334, Series 337, Series 349, Series 352, Series 355, Series 358, Series 369, Series 371, Series 373, Series 375, Series 384, Series 388, Series 390, Series 398, Series 400, Series 413, Series 414, Series 431, Series 432, Series 436, Series 447, Series 462, Series 464, Series 466, Series 468, Series 471, Series 474, Series 482, Series 484, Series 487, Series 490, Series 492, Series 493, Series 494, Series 511, Series 518, Series 519, Series 526, Series 529, Series 531, Series 532, Series 535, Series 538, Series 539, Series 540, Series 542, Series 543, Series 544, Series 545, Series 546

(Securities issued pursuant to Regulation A)

Item 7. Departure of Certain Officers

On September 1, 2026, Nigel Glenday resigned as Chief Executive Officer, Chief Financial Officer and a manager of the Company, and he also resigned from all other officer, manager and director positions held with other affiliates of Masterworks, effective as of 11:59 p.m. Eastern time on that date (the “Transition Date”). Mr. Glenday’s resignation was not the result of any disagreement with the Company, Masterworks, or their respective affiliates on any matter relating to the Company’s operations, policies, or practices.

Effective simultaneously with, and so as to avoid any vacancy resulting from, Mr. Glenday’s resignation, Scott Lynn was appointed to fill all roles vacated by Mr. Glenday, including serving as Chief Executive Officer, Chief Financial Officer, and as a manager of the Company. Mr. Lynn is the founder and Chief Executive Officer of Masterworks, LLC, the parent company that owns the Masterworks investment platform. There is no arrangement or understanding between Mr. Lynn and any other person pursuant to which Mr. Lynn was appointed to these positions, other than as described in this Item 7.

Following the Transition Date, it is expected that Mr. Glenday will continue to serve as a senior adviser to Masterworks, LLC and its affiliates.

SIGNATURES

Pursuant to the requirements of Regulation A, the issuer has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.