How to use this glossary
The Belgian investing world runs on a small set of terms that appear everywhere once you notice them — on your broker statement, in the tax return, in every guide on this site. Each entry below defines one term plainly and says where it shows up. These are descriptions of what the words mean, not instructions on what to do with them. Definitions can lag rule changes; confirm anything time-sensitive against a current official source.
TOB (taxe sur les opérations de bourse / beurstaks)
The Belgian tax on stock exchange transactions, due on every purchase and sale of a listed security. The rate — 0.12%, 0.35% or 1.32% — depends on the instrument, and each rate is capped per transaction. A Belgian broker withholds it; a foreign broker generally leaves it for you to file monthly.
Withholding tax (précompte mobilier / roerende voorheffing)
Tax deducted at source from investment income, chiefly dividends and interest. In Belgium the standard rate is 30%. When a broker does not withhold it — typically on foreign income through a foreign broker — the amount is settled in the annual return instead.
Capital-gains tax (meerwaardebelasting)
The 10% tax on realised gains on financial assets, in force from 2026. It applies to the gain — sale value minus cost basis — not to the whole sale, and only when a position is actually sold.
Step-up
The reset of an asset's cost basis to its market value on 31 December 2025. For anything held on that date, the capital-gains tax measures the gain from the step-up value, so growth that happened before 2026 is left outside the new tax.
Annual exemption
A yearly amount of realised capital gain that escapes the 10% tax before the rate applies. Only the gain above the exemption is taxed, which is why small realised gains can fall entirely within it.
FIFO (first in, first out)
The rule for deciding which units you sold when you bought the same security at different times. The earliest-purchased lots are treated as sold first, which fixes the cost basis used to measure the gain.
FBB / QFIE (quotité forfaitaire d'impôt étranger)
The mechanism that gives partial credit for foreign tax already withheld on certain foreign income, so the same income is not fully taxed twice. It is claimed in the annual return and depends on the treaty with the source country.
FSMA registration
Whether a fund is registered for public distribution in Belgium with the FSMA, the financial regulator. Registration — not where the fund is domiciled — is one of the conditions that decides which TOB rate its shares carry.
Accumulating vs distributing
Two share classes of the same fund. An accumulating class reinvests income internally and pays no dividend; a distributing class pays income out. The choice affects both the dividend withholding you see and, often, the TOB rate.
KID (key information document)
The short standardised fact sheet a fund must publish, covering its costs, risk and structure. It is where you confirm whether a fund is accumulating or distributing and check its identifiers.
ISIN
The unique twelve-character code that identifies a specific security. The country prefix (IE, LU, FR…) shows where the instrument is domiciled, which is not the same as where it is registered for sale.
Bordereau
The declaration form for the TOB — the statement summarising the transactions and tax due for a period, filed through MyMinfin when the broker did not withhold.
Donneur d'ordre
The person on whose instruction a transaction is carried out — the investor placing the order. On a foreign broker the donneur d'ordre is the one who owes the TOB, which is why it lands on you to declare.
Domicile vs registration
Two different facts about a fund that are easy to confuse. Domicile is the country the fund is legally based in (shown by the ISIN prefix). Registration is whether it is authorised for sale to the Belgian public. TOB treatment turns on registration, not domicile — the distinction behind several quirks in these guides.
Published 4 Sept 2026