When should expats file their income taxes?

Tax filing season vs. tax year: What's the difference?

Before diving into tax calendars around the world, it's worth clarifying a few key terms. Is there a difference between tax filing season (tax season) and the tax year? The answer is yes, the two expressions don't mean quite the same thing.

Tax filing season (tax season)

As the name suggests, tax filing season is a set period during which expats and residents must report the income they earned in the previous tax year. For example, in 2026, expats living in Canada have until April 30, 2026, to file their 2025 income.

Tax year

The tax year is also a defined period, but in this case, it refers to the timeframe used to calculate the income of individuals or businesses for tax purposes. The tax year may align with the calendar year, but it doesn't always. Some businesses, for instance, operate on a different fiscal cycle. When that's the case, the income tax return will be based on the company's specific tax year. Depending on their situation, expats should carefully check which tax year applies when reporting their previous year's income.

Filing your taxes: Tax years by country

Many countries align their tax year with the calendar year, running from January 1 to December 31. However, some countries use a tax year that differs from the standard calendar year.

Note that businesses may also be permitted to use a different tax year, subject to obtaining the necessary approvals and complying with the rules set by the laws of the country where they operate.

Countries where the tax year matches the calendar year

In most countries across Europe, Africa, and North and South America, the tax year runs alongside the calendar year: the United States, Canada, Argentina, Brazil, Senegal, Cameroon, Algeria, Cape Verde, the Comoros, Egypt, Tunisia, Belgium, France, Germany, Greece, Latvia, Estonia, Lithuania, and more. Several Asian countries, including Uzbekistan, China, South Korea, and Vietnam, follow the same system.

Countries where the tax Year differs from the calendar year

Namibia: April 1 to March 31 of the following year.

United Kingdom: April 6 to April 5 of the following year.

Australia: July 1 to June 30 of the following year.

Mauritius: July 1 to June 30 of the following year.

Japan, New Zealand, and India: April 1 to March 31 of the following year.

Tax filing deadlines for expats

A quick note on terminology: you'll often hear people talk about "filing their taxes." Strictly speaking, what you're actually filing is your income from the previous tax year, which then determines whether you owe taxes or not. Either way, knowing your filing deadline is essential. In many countries, online filing comes with an extended deadline. Here's an overview.

April deadlines

Estonia: February 16 to April 30.

Philippines, United States: April 15.

Singapore: April 18.

Chile, Mexico, Canada: April 30.

Brazil: generally April 30.

May deadlines

Sweden: by May 2 (May 4 at the latest).

Netherlands: before May 1.

South Korea: by May 31.

June deadlines

Spain: April 2 to June 30.

Greece: June 30 of the current year.

France: between May and June, depending on your department of residence.

The United Kingdom: A special case

United Kingdom: depending on their situation, expats may need to use the Self Assessment system, which allows HMRC (His Majesty's Revenue and Customs) to assess foreign income and self-employment earnings. In this case, the filing window runs from April 6 to October 31. The deadline for online submissions is extended to January 31 of the following year.

Do you still need to file a tax return if tax is withheld at source?

Many countries, including South Korea, Canada, the United States, and most of Europe, operate a withholding tax system. However, having tax withheld at source does not mean you're off the hook for filing an income tax return.

What are the implications of moving abroad mid-tax year?

First and foremost, you must notify the tax authority in the country you're leaving of your new address. Governments have significantly tightened measures to combat tax avoidance. Leaving a country in the hope of escaping taxation can, in fact, trigger a serious tax reassessment. Tax residency is another key issue to address: even after moving abroad, you may still be considered a tax resident of the country you left. If you relocate mid-tax year, you'll need to file a return for the income earned before your move, in the country you left. But you'll likely also need to file a return in your new country. To avoid being taxed twice on the same income, many countries have signed double taxation treaties. It's well worth consulting an international tax specialist to understand exactly where you stand.