Paying into pension and tax credits

[Itsallaboutme3]

I have recently started paying into work pension, around £80 a month, do i need to let hmrc knoww regarding working and child tax credit and will it affect it? Thanks

Yes and yes.

Only if the contributions are deducted from your net salary. If they are deducted from gross salary then your P60 will show the taxable pay as your gross pay-pension.