Tax overpaid of the first-year self assessement tax return

I submitted my first-year Self Assessment tax return for Tax Year 2023-2024 since I entered UK. Due to I did not work, I only relied on bank interest for income. My total income received was less than the personal allowance. Therefore, I no need to pay tax. However, I have a strange thing that why I got the tax overpaid to my bank account from HMRC as this was my first-year Self Assessment tax return.

Hi,
If you contact our Self Assessment team, we should be able to confirm where the overpayment you have received has come from.
Self Assessment: general enquiries
Thank you.