When submitting a tax return, HMRC needs a record of all the income you’ve earned and the tax you have paid. It all contributes to the tax calculation.
You won’t be taxed again if you’ve already paid the right amount of tax. In fact, some people find that they’ve overpaid tax on their employment and reporting it in a tax return is the quickest way to get a refund!
You can include details of your employment on the Tax tab. Tap As an employee and can add each employer that you worked for during the tax year. For each, you'll need to include its name, PAYE Reference, the total income you earned and the tax you paid. The best place to get this information is from your P60 or P45.
If you can't see As an employee, you can edit the income sources included by tapping the Add or remove an income source button below the income sources.