Benefits transferred to pension top-up, are they taxable?

Hi, I'm filling out my self-assessment tax return, and I've just noticed something I can't quite figure out how to input, if it needs to be input at all. This isn't specifically related to my self-employment income - it's my regular employment. The company I work for has a benefits system, but each year rather than use them for things like private insurance or other perks, I have them added to my pension payments as a top-up. When it asks for taxable benefits from your employer, would this count as a taxable benefit? If so, where on the self-assessment form should I mention it? Huge thanks for any thoughts.

Hi Dan,

This depends on whether it is payrolled or not.
f you received a P11D then yes.
You may want to confirm with your employer.

Thank you.