Service standard for response to claim for refund; postal delivery to HMRC

Tax year 2020 (covering 2019-20) ended on 5 April 2020. The four year deadline for filing an amended return and claiming a refund is 5 April 2024. I sent my amended return and claim for refund on 25 October 2023 to Self Assessment, HM Revenue and Customs, BX9 1AS, United Kingdom and the Royal Mail tracking service says that the envelope arrived at North West Midlands MC on 27 October, but I have not received a reply or even an acknowledgement. When should I expect to receive a reply? If it's not until after 5 April 2024, will I be prevented from correcting any errors?

Hi john2938,
You can expect a repy by 6 March 2024. as the claim was sent in prior to 5/4/24.
The 2019/20 year would still be reviewed even if there was a delay in HMRC processing it after 6/4/24.
Thank you. 

6 March 2024 has come and gone and still no reply. Can you provide an update?

Hi john2938

We will need to access your record to review this for you.
You can contact HMRC Income Tax: general enquiries

Thanks