A rate with a ceiling
The Belgian TOB (taxe sur les opérations de bourse / beurstaks) is a percentage of the transaction value — 0.12%, 0.35% or 1.32% depending on the instrument. But each rate comes with a cap per transaction, and the cap is what makes the effective rate on a large order lower than its headline percentage.
| Rate | Cap per transaction | Transaction value at which the cap bites |
|---|---|---|
| 0.12% | €1,300 | €1,083,333.33 |
| 0.35% | €1,600 | €457,142.85 |
| 1.32% | €4,000 | €303,030.30 |
Below the value in the last column, you pay the flat percentage. At and above it, you pay the cap — a fixed euro amount — no matter how much larger the order is. The cap is per transaction, not per day and not per month.
The effective rate falls above the cap
Once the cap applies, the rate you actually pay is the cap divided by the order value, and that figure only gets smaller as the order gets bigger. Take the 1.32% band, capped at €4,000:
| Order value | 1.32% before the cap | Actually paid | Effective rate |
|---|---|---|---|
| €100,000 | €1,320 | €1,320 | 1.32% |
| €303,030 | €4,000 | €4,000 | 1.32% |
| €500,000 | €6,600 | €4,000 | 0.80% |
| €1,000,000 | €13,200 | €4,000 | 0.40% |
At €303,030 the €4,000 cap is reached exactly. Beyond it the tax stops growing, so a €1,000,000 order carries the same €4,000 as a €303,030 one — an effective rate of 0.40% against a headline of 1.32%.
Why splitting a large order can cost more
Because the ceiling is per transaction, each separate order gets its own cap. For most trades that changes nothing — below the cap the tax is simply proportional, so one order or several comes to the same total.
For an order large enough to hit the cap, it works the other way. One €1,000,000 purchase in the 1.32% band pays a single €4,000 cap. The same million split into two €500,000 orders pays the cap twice — €4,000 + €4,000 = €8,000 — because each order reaches its own ceiling. Splitting has doubled the tax on an identical total position.
The same logic runs in reverse for orders below the cap: there, size and splitting make no difference to the rate, and the cap is simply never reached.
Keep it in proportion
These thresholds are high. The cap in the 1.32% band bites only above roughly €303,000 in a single transaction, and in the 0.12% band only above about €1.08 million — values most retail orders never approach. For an ordinary purchase the headline rate is the rate, and the cap is irrelevant.
Where it matters is the large, one-off transaction: a big lump sum going in, or a sizeable position being sold. There, the per-transaction ceiling is a genuine feature of the tax, and whether the trade is placed as one order or several changes what it costs.
The stock exchange tax simulator prices an order — cap included — on the spot.
Always verify your figures
Belfolio computes and presents these amounts for information only. This is not tax advice, and it is not a recommendation about how to structure a trade. The rates and caps are published by the FPS Finance — verify them there or with your accountant before relying on them.
Published 7 Aug 2026