Managing cross-border tax with Sable International Tax Australia

If your life spans more than one country, your wealth usually does too, along with your tax exposure.

As the world becomes more connected, managing tax across borders has become part of everyday life. Whether you are moving between Australia, the UK and South Africa, investing overseas or expanding a business internationally, your tax position can become more complex.

What used to be a niche issue is now part of everyday life for expats, returning residents, investors and business owners building their lives across borders.

To meet this growing demand, we have launched Sable International Tax Australia, providing dedicated support for managing tax across multiple jurisdictions.

Australian tax and ATO rules in a global context

Increasing international mobility is reshaping how global tax must be managed. Today, professionals regularly earn income in one country, live in a second, and hold property or investments in a third.

Under Australian Taxation Office (ATO) rules, tax residency and foreign income are not always straightforward. Once you add the UK and South African systems into the mix, things can become complicated, with each country applying its own rules in ways that do not always match.

The result is that your greatest tax exposure often arises between jurisdictions, not just within them.

Tax treaties and Double Taxation Agreements

Managing your tax affairs across countries is not just about filing separate returns in each one. The real challenge is understanding how different tax rules interact, including the impact of tax treaties and Double Taxation Agreements (DTAs)

While these treaties are designed to prevent you from being taxed twice on the same income, they do not eliminate risk automatically. Mismatches in treaty interpretation, timing, asset classification, and foreign tax credits can still lead to costly double taxation if not structured correctly.

Navigating how these treaties apply in practice is essential to protecting your assets and avoiding unintended liabilities.

Proactive planning: Where expert tax advice adds value 

Without clear cross-border tax planning, things can quickly become messy. Common risks include:

• Uncertainty around tax residency when countries apply different rules
• Paying tax twice on the same income or gains
• Reporting inconsistently across tax authorities
• Missing planning opportunities before moving or investing abroad
• Relying on advisers who only understand one system

A coordinated approach to cross-border tax

Sable International Tax Australia was established to bridge these gaps. Working closely with our teams in the UK and South Africa, we provide cross-border tax advice that looks at your finances as a whole, not as separate country filings.

Our approach ensures:

• One aligned strategy across Australia, the UK, and South Africa
• Defensible reporting that stands up to scrutiny from the ATO, HMRC, and SARS
• Complete visibility over your total global tax exposure
• No conflicting advice, duplication, or compliance gaps

See also: Our ASIC and business structuring services in Australia

Build your future beyond borders

Building a life across borders is about ensuring your financial foundation supports you every step of the way.

If you are managing income, assets, or residency across Australia, the UK, and South Africa, now is the time to take a coordinated approach.

FAQs

1. Do I need to file tax returns in multiple countries if I live in Australia?

Yes, in many cases you will. If you still earn income, own property or have business interests in countries like the UK or South Africa, you may have ongoing tax filing obligations there. While Australia taxes residents on worldwide income, other countries often require non-residents to declare locally sourced income such as rental income or capital gains.

2. How do Double Taxation Agreements prevent me from being taxed twice?

Double Taxation Agreements set out which country has the right to tax specific types of income. If both countries apply tax, the agreement allows you to claim relief, usually through foreign tax credits in your country of residence, so you are not taxed twice on the same income.

3. When is the best time to engage a cross-border tax adviser during a move?

The earlier, the better. Ideally, you should seek advice six to 12 months before relocating. This gives you time to structure your affairs properly, manage your tax residency status and avoid unnecessary tax exposure before it arises.

4. How does Sable International Tax Australia manage my position across Australia, the UK and South Africa?

We take a joined-up approach. Instead of separate advisers in each country, our teams work together to manage your position across Australia, the UK and South Africa as one coordinated strategy. This ensures your filings are consistent, compliant and aligned across the ATO, HMRC and SARS.

5. What happens if I am considered a tax resident in two countries at the same time?

This is where a Double Taxation Agreement becomes essential. Tie-breaker rules are applied to determine a single country of residence for tax purposes, based on factors such as where your permanent home is, where your main personal and financial ties are, and where you spend most of your time.

Get clear, expert guidance on your cross-border tax position. Speak to our team today at email: [email protected] or call +61 3 8651 4501.