Amended 2020/21 self assessment not yet reflected in tax code

I realised that I had missed an allowance from my 2020/21 self assessment and resubmitted it recently (29/12/22). I'm employed and the tax due for that year (2020/21) is being recovered via my tax code for this year (2022/23). The revised amount of tax due is correctly showing on my self assessment records. However, my tax code still reflects the old self assessment submission. Can I expect HMRC to automatically update my tax code at some point, or do I need to do something else to trigger that process?

Hi,

If you contact our Self Assessment team, we can confirm the amendment and update your tax code.

Self Assessment: general enquiries

Thank you.