Helping you calculate your Capital Gains
You are liable for tax gains made on worldwide property. 50% of the gain is liable for tax with inflation relief after two years. The gains are added to your other income and taxed at the standard income tax scale rates. There are other implications in terms of buying a second home, investing in property in the UK or EU and investment in shares.
As a non-resident, you will pay tax on 100% of the capital gain from a property sale at 28%. For UK residents, the gain would also be taxable in the UK, but for tax paid in Portugal, this can be credited against the amount due in the UK.