Taxes

Online trading platform? Beware the tax backlash.

In Belgium, every purchase or sale of securities triggers the stock-exchange tax (TOB). The real question isn’t whether you owe it — it’s who handles it. And the answer depends entirely on your platform.

The rule, simply

An intermediary established in Belgium is legally liable for the TOB: it withholds and pays it for you. An intermediary established abroad is not — so it is you, the Belgian-resident investor, who must declare and pay it, unless you can prove it has already been paid.

Where does your platform stand?

PlatformWithholds the TOB?Withholds capital gains?Who handles it
Bolero (KBC), Keytrade Bank, MeDirect, ING, BNP Paribas Fortis, Belfius, Saxo (Belgian branch)✅ Yes✅ Yes (opt-in, opt-out possible)The platform — TOB and capital gains withheld at source
DEGIRO, MEXEM, BUX, Lynx⚙️ Service (often on by default)❌ NoTOB by the platform (check your settings); capital gains on you
Trade Republic, Revolut, eToro, Interactive Brokers (direct), N26❌ No❌ NoYou (TOB and capital gains)
⚠️ Using a platform from the last row? You are legally responsible for the TOB. This page is for you.

If it’s you: here’s what it means

The TOB must be declared for each transaction via form 275, on MyMinfin, no later than the last business day of the second month following the transaction. Overlooked or forgotten, the obligation exposes you to penalties.

The penalties

And it’s not the only obligation

On a foreign platform, the new capital-gains tax and the reporting of your foreign account also rest on your shoulders.

Benchmarkr sheds light

Bring your accounts together: Benchmarkr computes your stock-exchange tax from your aggregated transactions and periodically prepares a view of the taxes you owe. Clarity, continuously.

Estimate my stock-exchange tax

Sources

Benchmarkr is an assistance and calculation tool. It does not constitute personalized tax advice. Platform statuses may change — check with your intermediary. Updated: 2026