I am studying for my self assessment qualification and have a friend who is self employed and after doing his own self assessment didn't need to use any of his personal allowance as his net income was below £6475, he has informed me that if you don't use up any or only part of your personal allowance you can actually carry it over to your next years tax return to add it to your p.a of that year to reduce the tax due if required, i'm not so sure this is correct can anyone clarify this please.
No it i not correct. The personal allowance is currently 6475 for a year - over that you pay tax, under it you don't but may have to pay 8% NI if net income over 5175. You cannot carry any underspend to the following year. Use it or lose it!!!