Pension contribution - which tax year?

I am writing to seek clarification on a specific scenario regarding pension contributions made via salary sacrifice and how they relate to the annual allowance. The scenario is as follows: 1. An employee received a bonus of £40,000 in March 2023. 2. The entire bonus was sacrificed for additional pension contributions. 3. This sacrifice is reflected on the employee's payslip dated 15 March 2023. 4. However, due to administrative processes, the pension provider did not receive the contribution until after 5 April 2023 (i.e., in the 2023/2024 tax year). My specific query is: For the purposes of the annual allowance, would this £40,000 contribution count towards the 2022/2023 tax year (when the sacrifice was made and appeared on the payslip) or the 2023/2024 tax year (when the pension provider received the funds)? I would greatly appreciate your guidance on this matter to ensure correct reporting and compliance with pension contribution rules.

Hi,
A salary sacrifice would just mean they would not get the bonus. It becomes company money and can be used to give an employer contribution to the pension.
Thank you.