Guide

The Belgian investor’s tax guide.

Investing via an online bank or a foreign app? Three tax obligations rest on you — often without you knowing. Here’s how to find your way.

Why these obligations fall on you

When you invest through a Belgian bank, it handles almost everything: it withholds the stock-exchange tax, deducts capital-gains tax, and reports what needs reporting. By moving to a foreign platform — Trade Republic, Revolut, eToro, Interactive Brokers — you gained lower fees and a modern interface. You also inherited, without anyone telling you, the obligations your bank used to meet on your behalf. There are three of them, independent of one another, and overlooking them exposes you to penalties.

The stock-exchange tax (TOB): on every transaction

Every purchase and every sale of securities triggers a tax on stock-exchange transactions. A platform established in Belgium withholds and pays it for you. A platform established abroad does not: legally, it is then you who must declare and pay it — for each transaction, within a short deadline. It is the most frequent obligation, because it triggers on every move, and the most often overlooked.

See which platforms withhold the TOB

Capital-gains tax: the 2026 choice

Since 1 January 2026, capital gains on financial assets are taxed at 10%. Behind that single rate lies a choice: opt-in, where your Belgian intermediary withholds at source, or opt-out, where you declare yourself. The default is opt-in — and it ignores both your €10,000 exemption and losses realised elsewhere. On a foreign platform the question is moot: you file personally anyway.

Understand opt-in and opt-out

Your foreign account: two filings

Holding a securities account outside Belgium creates two obligations separate from taxes: report the account once to the National Bank’s Central Point of Contact, and mention it every year in section XIII of your return. One does not replace the other. This has applied since 2015 and covers cash accounts too.

See the step-by-step procedure

Beyond tax: your wealth

Once your transactions are brought together for the tax computation, the same view serves another purpose: knowing where you stand. How much you hold, spread how, concentrated where. It is the view a private banker would take on your allocation, without the private-banking entry ticket.

See the wealth view

Where to start

The three tax obligations do not trigger at the same time. The stock-exchange tax follows every transaction, the account filing happens once then every year, and the opt-in / opt-out choice comes up annually. What they share: all of them require knowing what you hold and what you actually realised. That is where to start.

Everything in one place

Benchmarkr brings your transactions together, computes your taxes and helps you stay compliant — without paying more than necessary.

Review my taxes

Benchmarkr is an assistance and calculation tool. It does not constitute personalized tax advice or investment advice.