6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of August 2021

Commission File Number 001-15170

GlaxoSmithKline plc

(Translation of registrant's name into English)

980 Great West Road, Brentford, Middlesex, TW8 9GS

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F . . . .X. . . . Form 40-F . . . . . . . .

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ____

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ____

GlaxoSmithKline plc

Block listing Application

Application has been made to the Financial Conduct Authority and the London Stock Exchange plc for a total of 3,230,000 Ordinary Shares of 25p each ('Shares') to be admitted to the Official List.

The Shares are being reserved under an existing block listing and will be issued under the GlaxoSmithKline plc Share Save Plan 2012 and GlaxoSmithKline plc 2017 Deferred Annual Bonus Plan.

When issued, the Shares will rank pari passu with the existing Ordinary Shares of 25p each.

Admission is expected to be effective on 6 August 2021.

V A Whyte

Company Secretary

5 August 2021

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorised.