Company: HBCYF
Filing Date: 2025-05-13
Form Type: 6-K
Source: 0001193125-25-118864
Chunk: 0

Company: HSBC HOLDINGS PLC
Filing Date: 2025-05-13
Form: 6-K
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2025

Commission File Number: 001-14930

HSBC Holdings plc

8 Canada Square, London E14 5HQ, England

(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 ☒ Form 40-F ☐

This Report on Form 6-Kis hereby incorporated by reference in the following HSBC Holdings plc

registration statement: file number 333-277306

HSBC Holdings plc (the “Registrant”) hereby incorporates by reference the following exhibits to this report on Form 6-Kinto its registration statement: file number 333-277306.

| Exhibit No. 
 4.1         
 5.1         |     | Description of Document                                                                                         
 Thirty-sixth Supplemental Indenture to the Senior Securities Indenture, dated May 13, 2025.                     
 Opinion of Cleary Gottlieb Steen & Hamilton LLP, special US counsel to the Registrant, dated May 13, 2025.      |
|:------------|:----|:----------------------------------------------------------------------------------------------------------------|
| 5.2         |     | Opinion of Cleary Gottlieb Steen & Hamilton LLP, special English counsel to the Registrant, dated May 13, 2025. |

SIGNATURE 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 authorized.

| Date: May 13, 2025 |     | HSBC Holdings plc 
 By:               |     | /s/ James Murphy                |
|:-------------------|:----|:------------------|:----|:--------------------------------|
|                    |     | Name:             |     | James Murphy                    |
|                    |     | Title:            |     | Global Head of Markets Treasury |

[ Signature Page to Form 6-K Relating to the Senior Issuance]