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 20, 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 270, Series 274, Series 275, Series 276, Series 279, Series 280, Series 282, Series 283, Series 284, Series 285, Series 287, Series 288, Series 289

(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.