mistake in form SA-1 about sources of income

John filled on form SA-1 that he will not have foreign income over 300. But that was a mistake and John's foreign income might actually just cross 300. But if John has already got a UTR number assigned through that incorrect form SA-1, is it necessary and possible to do anything to correct the form SA-1 that John submitted? or can John just report the accurate foreign income in the self assessment return and not do anything about the already submitted form SA-1?

Hi,
You can just report the accurate foreign income when you submit your Self Assessment return.
Thank you.