Incorrect Tax deducted within CGT calculation

The CGT self submission form is showing an overpayment for the 2022/2023 tax year. This is due to the form stating I paid £15,367 in 2022/2023. This does not align with my payslips or salary that was shared with me by my employer at that time. I believe I paid closer to £4k in taxes in that period. How do I ensure that the data in HMRC is correct? I do not beleive i am due a refund, i believe i owe £2k and do not want to incorrectly claim a refund! Thank you.

Hi

If you mean the full tax return rather than the property disposal form, you can check the employment details on the return to ensure your correct pay and tax has been entered.
You also need to include the gain that you made and if it has already been report, include the tax already paid - the CGT tax only in that particular section.

Thank you