Moving to the UK? How to finalise your South African and UK tax obligations

Many South Africans believe that filing tax returns in one country automatically covers them in the other. Unfortunately, that’s not the case. Both South Africa and the UK have their own tax systems and obligations, and it’s crucial to stay compliant in both jurisdictions.

While you can’t tax emigrate until after departure, it’s a good idea to engage with your tax practitioner early to understand the process and gather the necessary documentation, and to establish your UK tax profile as soon as you arrive.

Finalising your South African taxes

Typically, you will remain a South African tax resident until you have physically left the country, and SARS has approved your change in tax status through the formal process of tax emigration. SARS will allow you to backdate your tax emigration date accordingly, so it’s important that you retain evidence of your exit from South Africa.

Your tax practitioner can help you assess when your South African tax residency is likely to cease and when your UK tax residency will begin. These dates can straddle different tax years in each jurisdiction, which means you may need to file in both countries for the same tax year. Preparing in advance ensures you understand your obligations to both SARS and HMRC so you can avoid double taxation or compliance issues.

When you end your South African tax residency, SARS treats it as if you’ve sold all your worldwide assets (except South African property). This can trigger an exit tax, which is a form of tax payable on the deemed disposal of certain assets.

Once you’ve paid any exit tax due and your non-resident status is confirmed, you’ll only be taxed on income sourced in South Africa, such as local rental income or dividends.

Completing this process properly ensures:

• You pay the right taxes in the right countries
• You avoid double taxation
• You start fresh in the UK with a clean tax position

Setting up your UK tax life

When you move to the UK to live or work, one of the first things you need to do is apply for a National Insurance (NI) number. This can be done online through HMRC’s website.

We’ve had a few clients experience issues when HMRC declines to issue an NI number if the applicant doesn’t plan to work in the UK. This might not seem important at first, but it can cause problems later, especially if you need to:

• Report foreign earnings
• Complete your South African tax emigration
• Prove your UK tax residency

Without an NI number, HMRC can’t verify your UK tax status, which can delay important filings and compliance steps.

Unlike other countries, you’re not automatically required to file a Self-Assessment tax return in the UK. You’ll need to file a return if, for example:

• You’re self-employed or operate through your own limited company.
• You earn foreign income, and need to report it or make a claim under the Foreign Income and Gains (FIG) regime.
• You earn more than £10,000 in investment income (for smaller amounts, you just need to inform HMRC)
• You are liable for the High-Income Child Benefit Charge
• You have Capital Gains Tax to pay

Once you register for Self-Assessment, HMRC will issue a Unique Taxpayer Reference (UTR) number. This allows you to file your tax return online or by post.

See also: Why it pays to do your UK Self-Assessment tax return early

Managing taxes across both jurisdictions

The UK and South Africa have a Double Taxation Agreement (DTA) that prevents you from being taxed twice on the same income. But to benefit from it, you must be correctly registered in both systems.

By properly managing your tax residency and obligations in both countries, you’ll:

• Stay compliant with SARS and HMRC
• Avoid unnecessary tax liabilities or penalties
• Ensure you’re taxed only where appropriate
• Gain peace of mind as you settle into your new life abroad

How we can help

Our cross-border tax specialists help South Africans navigate the transition from SA to UK tax with confidence. We can:

• Determine your tax residency status
• Complete your tax emigration and handle exit tax
• Assist with your UTR application
• Advise on how DTAs affect your tax position

Your global journey starts with the right partner. Whether you’re finalising your South African tax residency, setting up your UK Self-Assessment, or navigating complex foreign income reporting, our team will guide you every step of the way. Get in touch with our expert advisers and start building your future beyond borders. Email us today at [email protected] or call +44 (0) 20 7759 7553.