Choosing a broker in Belgium: start with the paperwork, not the fees

Why the paperwork comes first

Broker comparisons are almost always about transaction fees. That is understandable — it is the number on the home page — but for most people placing a few orders a year, the gap between two brokers there is a matter of a few euros.

The gap in paperwork is not. Two investors with exactly the same portfolio can end the year one with a monthly filing and the other with none at all. That gap costs no euros but hours, and it is the kind of gap you discover in May, when the return opens.

So this is neither a ranking nor a recommendation. It is a list of things you can check before you sign, on the understanding that what suits you depends on which work you would rather not do yourself.

Four questions that decide most of the work

1. Does it withhold the stock exchange tax?

The stock exchange tax is due on every purchase and every sale. If your broker withholds it, that is settled. If not, you file it every month yourself through MyMinfin, with its own deadline per month — including months in which you placed a single order. What that filing looks like is set out step by step in the MyMinfin self-declaration guide, and what an order costs is worked out by the stock exchange tax simulator.

It is the heaviest of the four, because it is the only one that repeats. Filed late, it accrues a fee per week of delay, which the penalty simulator puts a figure on.

2. Does it withhold the dividend withholding tax?

At 30% on dividends, this is the most expensive one to get wrong. Where it is not withheld, the gross dividend goes on your annual return. On foreign dividends a second layer sits on top: a withholding tax in the country of origin, with its own formalities for limiting it.

3. Does it withhold the capital-gains tax — and from when?

Since 2026 there is a 10% tax on gains. Belgian intermediaries withhold it at source as a rule from June 2026, but "Belgian" does not mean "withholds": a broker running the opt-out system withholds nothing and leaves the filing to you.

And one thing holds either way: the €10,000 annual exemption is always claimed back through the annual return, even when the 10% was already withheld at source. Withheld is not the same as settled.

4. Do you get a Belgian tax certificate?

A certificate maps your year onto the Belgian tax boxes. Without one you get a complete activity statement and do the translation yourself — including the exchange rates if you traded in dollars.

What each broker does on these four points, and where we got it, is in the broker tax comparison. Every cell says what kind of source it rests on, and where we are not sure, that is written there too.

A fifth question that has nothing to do with tax

If the broker is established outside Belgium, one duty attaches to the account itself rather than to what you do with it: registering the foreign account with the National Bank's Central Point of Contact, and then mentioning it each year in box XIII of your return. It applies from the first euro and it is the thing most often missed in the first year.

If you hold accounts at more than one broker, it stays one return: multiple brokers, one Belgian tax return describes what has to be added together.

What you will not find in this comparison

No score, no ranking and no "best broker". Three reasons, all practical.

First, the tax is the same everywhere: it is a tax, not a price. A table showing a varying money column beside broker names would be read as a price comparison, and that would be untrue.

Second, the answer depends on what you hold and how often you trade. Someone adding to a position once a year weighs a monthly filing differently from someone trading weekly.

Third, performance is not in it and will not be. What a broker does with your taxes is a fact; what your portfolio will return is not.

Always verify your figures

Belfolio computes and presents these amounts for information only. This is not tax advice nor investment advice. Brokers change their practice, and several of the positions above are flagged by us as not yet settled; verify them with your broker and with the FPS Finance before filing.