Hi,
As you began working for your current employer on March 20th 2023, your part salary payment and sign on bonus may have been included in your 2022 to 2023 P60, and as such would have been taxed in that year. You would therefore only need to include your 2023 to 2024 P60 figures in your 2023 to 2024 tax return.
If you would like us to check your 2022 to 2023 pay and tax figures submitted by your employer, though, you can contact our Self Assessment team.
Self Assessment: general enquiries
Thank you.