Are Bonuses Pensionable?

Hi, I came to the UK on March 2020 and since then, work as an employee for a financial firm. Recently, I've been reviewing all my past payslips. I noticed that while I've had Pension deductions on my Bonus Payments for 2022 and 2023, I've not had any pension deductions done (Neither employee or employer contribution) on my 2021 Bonus amount. To be precise, I receive my Bonus every year on the last date of February. When I asked my employer, I was told that it was not mandatory to deduct Pension from Bonuses as on Feb 2021, but it was later on (Feb 2022 and Feb 2023). I'd like to understand: 1. Whether as on Feb 2021, Bonuses were pensionable (Both employee's and employer's contributions)? 2. If yes, are there any official word or regulation from HMRC or a relevant regulatory body stating the same. 3. What was the minimum % of employee and employer contribution towards pension as on Feb 2021, Feb 2022 and Feb 2023?

Hi Dinesh Sairam,
Bonues are relevant UK earnings to which tax relief can apply for pension contributions but there is no requirement for your employer to include a bonus as pensionable income when deducting contributions.
Thank you.