2 UTRs were accidently assigned to me last year 2022/23. Which one should I apply in 2023/24?

I was accidentally assigned 2 UTRs last year 2022/23: xxxxxx4546 and xxxxxx3334. I applied xxxxxx4546 for filing Self Assessment tax return in 2022/23. My Personal Tax Account is also marked with xxxxxx4546. However, a letter dated early April 2024 told me that my correct UTR should be another one: xxxxxx3334. I would like to know which UTR I should apply for filing my tax return in the coming tax years. I also cannot update my Personal Tax Account with the UTR xxxxxx3334 because last year I used xxxxxx4546 for filing.

Hi,

To give you the right advice here, we would need to access your record. Contact us by webchat or phone via:

Self Assessment: general enquiries

to allow us to do this.

Thank you.