Thanks for your reply.
For my saving interests from non-UK (i.e. foreign) bank accounts, should I categorise it under
(1) I'm getting taxable foreign income of £300 a year or more; OR
(2) I've untaxed income which cannot be coded in PAYE
I am filling in the SA1 form for self-assessment registration. For the tax year 2022-23, I have only interest income from UK and non-UK bank accounts saving. While I am filling in the form, under the section "why do you need to complete a tax return", should I just complete the category "Date untaxed income received from"? Really appreciate your guidance.