Personal saving lower than 10K - how and when would HMRC contact me to pay tax?

Dear HMRC team, I am employed and tax is deducted from my payroll. I have not registered for UTR before, since I did not have any self-assessment. For the 2023/2024 tax year, I have earned interest(less than 10K) from my Bank savings account. Other than that, I do not have any other income. Please let me know if my understanding is correct: >I do not need to register for a UTR number(SA1), and do not need to send the self-assessment form(SA100) to notify HMRC about my interest earnings. Am I right? If yes, how and when would HMRC contact me to pay the tax from my interest income? I am a bit worried if my understanding is not correct, and if I do not send SA100 to notify my interest income and end up I will need to pay a penalty. Thank you for your advice, HMRC team.

Looking forward to hearing from you, HMRC team.

Hi,

If the untaxed interest is less than £10000, then you would not meet Self Assessment criteira for this. You can check if you meet Self Assessment criteria here:

Check if you need to send a Self Assessment tax return

If you do not need to complete a Self Assessment, then once HMRC receives your PAYE income and details of the untaxed interest received from the banks and building societies, we will review your record. If you have underpaid, we will issue a calculation to you with details of how the underpayment will be collected. 

Thank you.