Dennison67

My situation: My employer and I were making contributions during the past tax year to NEST. I was contributing £1000 per month and my employer £150 (the numbers are indicative). My employer filed one month incorrectly on the NEST platform and that means that for this month the contributions look vice versa, i.e. my contribution as £150 and my employer's contribution as £1000. Therefore, for this month, tax relief was not claimed on the correct amount (it was claimed on £150 instead of £1000). My payslips show the correct contributions and my employer says that they made a mistake. However, neither NEST nor my employer seem to be able (or willing?) to fix this mistake, because my employer no longer has access to the platform. My question: Since NEST has not claimed the 20% of tax relief on the additional £850, would I be able to do so via my self-assessment? Would HMRC have a problem with this since NEST has the incorrect amounts filed in their records? (although I do have my payslips showing the correct amounts as I said) Thanks in advance