GLAXF GSK Plc (PK)

Filed Pursuant to Rule 433

Registration Nos. 333-223982 and 333-223982-02

September 28, 2020

FIXED RATE NOTES PRICING TERM SHEET

GlaxoSmithKline Capital plc

$1,250,000,000 0.534% Notes due 2023

Fully and unconditionally guaranteed by

GlaxoSmithKline plc

No PRIIPs KID – No PRIIPs key information document (KID) has been prepared as the Notes are not available to retail clients in the EEA or the U.K.

Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawal at any time.

To the extent that Standard Chartered Bank intends to effect any offers or sales of any Notes in the United States, it will do so through one or more U.S. registered broker dealers in a manner consistent with applicable law and regulations.

The Notes may not be publicly offered, directly or indirectly, in Switzerland within the meaning of the Swiss Financial Services Act (“FinSA”) and no application has or will be made to admit the Notes to trading on any trading venue (exchange or multilateral trading facility) in Switzerland. Neither this prospectus supplement, nor the accompanying prospectus, nor any other offering or marketing material relating to the Notes, constitutes or will constitute a prospectus pursuant to the FinSA, and neither this prospectus supplement, nor the accompanying prospectus nor any other offering or marketing material relating to the Notes may be publicly distributed or otherwise made publicly available in Switzerland.

The issuer and the guarantor have filed a registration statement (including a prospectus) and a preliminary prospectus supplement with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement, the preliminary prospectus supplement and other documents the issuer and the guarantor have filed with the SEC for more complete information about the issuer, the guarantor and this offering.

You may get these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus and the preliminary prospectus supplement if you request it by calling BofA Securities, Inc. toll-free at 1-800-294-1322, Citigroup Global Markets Inc. toll-free at 1-800-831-9146, Credit Suisse Securities (USA) LLC toll-free at 1-800-221-1037 and Morgan Stanley & Co. LLC toll-free at 1-800-584-6837.