Income from abroad
Earning money from outside Belgium, or working for a foreign employer while living here, raises questions most people never had to think about back home. The good news is that Belgium has clear rules and tax treaties in place for exactly this situation, so you rarely have to work it out alone.
This page explains how foreign income is taxed, how double taxation is avoided, and what changes if you work remotely for a non-Belgian employer.
Overview
How your foreign income is treated depends on where the income comes from, whether Belgium has a tax treaty with that country, and whether you are actively working there or simply receiving passive income like rent or dividends. The rules differ for each, so it helps to know which situation applies to you.
Declaring foreign income
If you are a Belgian tax resident, you are taxed on your worldwide income, which means foreign income needs to be declared on your Belgian tax return alongside your Belgian income.
This can include:
- A salary from a foreign employer.
- Rental income from property you own abroad.
- Dividends or interest from foreign investments.
- A pension paid from another country.
Even if the income was already taxed abroad, it usually still needs to be reported in Belgium - reporting it does not automatically mean you pay tax on it twice.
Declaring foreign income
Avoiding double taxation
Belgium has signed double taxation treaties with many countries, which determine which country has the right to tax specific income and how the other country accounts for it. Depending on the treaty, this usually works through one of two methods:
- Exemption with progression reservation: the foreign income is exempt from Belgian tax, but still counts when calculating the tax rate on your other income.
- Tax credit: the tax already paid abroad is credited against what you owe in Belgium.
The exact rules depend on the country and type of income involved, so check the specific treaty on the FPS Finance website or ask a tax adviser if your situation is not straightforward.
Working remotely for a non-Belgian employer
If you live in Belgium but work remotely for an employer based elsewhere, you are usually still considered to be working in Belgium for tax purposes, since that is where the work is physically carried out. This means:
- Your income is generally taxable in Belgium, even if your employer pays you from abroad.
- Your employer may need to register in Belgium to handle payroll correctly, depending on the arrangement.
- If this is not set up correctly, it can create complications for both you and your employer, so it is worth raising early with HR or a specialist rather than assuming it will sort itself out.
Social security across borders
Within the EU, EEA, and Switzerland, you are normally covered by the social security system of only one country at a time, usually determined by where you actually work. If you are temporarily posted to Belgium by a foreign employer, an A1 certificate confirms which country's social security applies and prevents you from paying into two systems at once.
If your situation involves multiple countries, it is worth confirming your position directly with the Federal Public Service - Social Security rather than assuming your home country's rules still apply.
Good to know: cross-border income and remote work situations vary a lot from person to person, and getting them wrong can be costly to fix later. If your situation involves more than one country, it is worth a one-off consultation with a tax adviser early on, even if everything else on this page seems straightforward.
Sources
- Belgium.be
- Federal Public Service - Social Security
- FPS Finance - Taxation
- FPS Finance
