Tax across borders

Moving country can change where you are tax resident, which income must be reported and how investments, companies, pensions and property are treated. The result rarely follows citizenship alone.

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Questions to answer

Where are you tax resident?

Review day-count tests alongside home, family, work and economic ties. Some countries use several tests rather than a single number of days.

Which income is in scope?

Salary, freelance revenue, dividends, interest, rent, pensions, capital gains and company benefits may be categorised differently across jurisdictions.

Does a tax treaty apply?

A treaty may allocate taxing rights or provide double-tax relief, but it does not automatically remove filing duties in either country.

What changed on the moving date?

A mid-year move can create split-year issues, new reporting periods and valuation questions for assets held before arrival.

Practical sequence

Your first five steps

01
Build a timeline of where you lived and worked, including travel days.
02
List income, assets, pensions, property and companies in every country.
03
Preserve payslips, brokerage statements, tax returns and proof of taxes already paid.
04
Check registration and filing deadlines in both the new and former country.
05
Ask an adviser to document the residence and treaty position—not merely give a verbal conclusion.

Common mistakes

What to watch for

The 183-day shortcut

Day count is important in many systems, but it is not a universal rule and can be overridden by other domestic or treaty tests.

Ignoring foreign accounts

Reporting can apply even where no additional tax is due, and financial institutions may exchange residence information.

Running a company from abroad

Where management decisions are made can create company tax, payroll or permanent-establishment questions separate from your personal return.

The country lens

Location changes the answer.

Tax years, residence tests, remittance rules, wealth taxes, capital-gains treatment and treaty networks differ substantially. Advice must cover both sides of the move and the interaction between them.

See the Thailand edition ↗

When to get help

Know where guidance ends.

Cross-border tax advice is sensible when you own property or companies, receive income from several countries, have significant investments, exercise share options, draw pensions or may be resident in two places.