A very exciting question about pensions and self employed tax return

[Moonlightstars]

This is a really exciting topic so please can we keep it civil 😁
Can anyone help, I tried googling, HMRC website and ringing HMRC but can't get through or find the info.

I am employed 3 days a week and over pay into my pension through this.
I am self employed 2 days a week so submit a self employed tax return. When I give HMRC figures how do they know not to tax me for the bit I put in my pension?
I only my seem to need to give HMRC the following
A) my pay before tax taken off
b) the tax paid through my employee.

I worried they think that I am earning a certain amount but not paying enough tax very much through my employee because they can't see the bit that goes into the pension?

Any ideas would be most appreciated.
I have asked finance but they are not sure (very small org!)

When you pay into your pension from your employed income, do you do it via salary sacrifice (which is the most normal way)?

If so, the income you report from your employment is the income after the pension contribution has been taken off. HMRC therefore don’t need to “see” the pension contribution as it is irrelevant for tax.

If you pay into a pension yourself from your post tax income then that is treated differently and you would declare it so you could potentially get the tax back.

You could fill in a tax return ?

That’s … what she’s trying to do

@DangerMouseAndPenfoldx thank you so much. I do that makes it's a lot simpler!
I can now file my tax return without that worry.