Incorrect Tax Calculation for the Year 6 April 2023 to 5 April 2024

Dear HMRC, I received a letter today stating that I owe £608 in taxes for the period 6 April 2023 to 5 April 2024. However, upon reviewing my payslip, I noticed that HMRC seems to have counted my entire March 2023 salary in the calculation. My payslip, issued on 8 April 2023, should only just count salary for the last two days of 6 april to 8 april, as the rest of my March earnings were already taxed in the previous tax year. My March payslip shows earnings of £777.50, and I believe only the portion corresponding to the final two days should be considered for this tax year. Could you please advise on how to resolve this issue? Thank you for your assistance. Kind regards,

Hi chun li,
You will have to speak with your employer, as we are notified by them of which tax year your income is paid in.
The tax year ends on the 5th April, so you will need to check with your employer how they have declared this to HMRC.
Thank you.