If you’re self-employed, or have money coming in from rent or investments, you’ll need to fill out a tax return for the year. If you’re planning to travel overseas, make sure you take everything you need to do it online while you’re away.
If you’re going to work abroad, you may still have to pay some UK income tax on sources of income from the UK like a rental property, savings or a pension. See HMRC for details.
If you stop work mid-way through the tax year, which runs April 6 – April 5, you are likely to have overpaid, and you could be entitled to a tax rebate. Contact HMRC to claim it.