Until you break UK residence, nothing changes
The UK taxes residents on worldwide income, so Cairo or Hurghada only changes your tax position once you are non-resident under the Statutory Residence Test. The usual route for working movers is the third automatic overseas test: full-time work abroad averaging at least 35 hours a week, fewer than 91 UK days and no more than 30 UK workdays. If you leave part-way through a tax year, split-year treatment can tax you as non-resident from your departure date. It is claimed on the SA109 residence pages of your final Self Assessment return, which HMRC's free online service cannot file, so you will generally need commercial software or an agent; the P85 is only for leavers who are not in Self Assessment.
What stays UK-taxable, and the pension exception
Non-residents still pay UK tax on UK-source income. Rental profits fall under the Non-Resident Landlord Scheme, with basic rate tax deducted by your agent or tenant unless HMRC approves gross payment, and gains on UK property must be reported and any tax paid within 60 days of completion, even where no tax is due. Pensions are the pleasant surprise on this corridor: Article 18 of the 1977 UK-Egypt treaty gives your state of residence sole taxing rights over most private and occupational pensions, so once you are treaty-resident in Egypt they can be relieved from UK tax by a treaty claim. UK government service pensions generally stay UK-taxable. One trap: the treaty gives no right to UK personal allowances, so while British citizens keep the Personal Allowance under UK domestic law, an Egyptian national with UK rental income generally does not.
The Egypt side, and the catch-up if you are years behind
Egypt taxes residents at progressive rates up to 27.5%, but its net is quasi-territorial: foreign income is only caught where the centre of your commercial, industrial or professional activity is in Egypt, which often leaves UK pensions and offshore portfolios outside Egyptian tax. A steady stream of this corridor is people who moved years ago, kept a UK rental and never filed; the fix is a voluntary disclosure through HMRC's Let Property Campaign, commonly spanning up to six years where the failure was careless, and coming forward unprompted is treated far better than waiting for HMRC's letter. The full picture, including the treaty articles and the disclosure route, is in our guide to UK tax when moving to Egypt. We handle the UK side on fixed fees agreed upfront, and a free clarity call will tell you what actually needs doing before you commit to anything.