If I include Employment income on my self-assessment will I be double taxed then?
Self assessment is a consolidation of all your personal income for the tax year. It is also importantly a consolidation of all the income taxes that you would have paid on that income. Therefore, employment income is included together with the income taxes that you would have paid on that income.
So when it is time for your self assessment to be submitted, it is important to submit all your P60s and P45s from all various employments that you held for the year. HMRC will need all that information to match with what they already have on your record.
If you’re unsure about filing your tax return or how to put together all your incomes, it’s always best to seek advice from an accountant or tax adviser.