Using basic PAYE tools, what figure goes in employer pension contribution when pension is RAS

(RAS means relief at source - not net pay pension provider such as NEST) I am a new employer so this may be a basic question. To deduct pension contributions for the employee, the pension provider says to subtract £520 (for 22/23) from total monthly pay and multiply this by 5% representing the employee monthly contribution. For simplicity, let's say the pensionable amount is £500 so £5% would be £25 However, when I make the payment, the pension provider autocalculates and does not charge me £25.00, but only about £20 for the pension contribution from the employee (I assume the remainder is the tax that it claws back). So when I fill in the PAYE tools form each time a payment is made, do I put the gross amount (£25) or the amount that I actually pay to the pension provider i.e £20? I assume it is the gross amount but would like to check. I have actually submitted the last FPS unfortunately so how do I correct if I am wrong (the tax will be correct - it is only the pension contributions that will be inaccurate). Many thanks

Hi
You would enter the amount you deduct from the employee so in your example this would £20.
Thankyou.

Many thanks, that's really useful

Hello HMRC Admin 10, i wonder if you could help me with another question related to pensions & PAYE software tool: As a director of my company i didnt have any pension details to add when first setting up the PAYE software tool many years ago, however i have just started a workplace pension with NEST. Do I need to go in to 'Starter details' & edit things there or just make sure I include the qualifying amount in my employee submissions? many thanks James

Hi James Bednarski
You should include the employee pension contributions when adding on your payment details.
To do this, you need to select 'manage employees', then select your name from the list, then select 'employee payments' and then 'add an employee payment'.
Once you have added in your payment date and payment amount, you will see a section for pension payments.
You can include the employee contributions there.
You must take care to add them to the correct box.
Your contributions will either be from the Net Pay arrangment or the Not Net Pay arrangment.
If you are unsure which applies, you will need to contact your pension provider. 
Thankyou.