Every broker sees a fragment
An investor holding positions at a Belgian broker, at DEGIRO and at Interactive Brokers has three account statements and no complete picture. Each platform reports what passed through it: its own purchases, its own disposals, its own dividends, its own withholding.
Belgian tax does not work at that resolution. It taxes the person, not the account. The exemption, the loss offsets and the final settlement are computed once, on the whole of a taxpayer's realized result for the year.
That mismatch — three partial views, one taxpayer — is the whole subject of this article.
What the mismatch costs
The €10,000 exemption is one per taxpayer. Not one per broker, not one per account. Someone realizing gains at three brokers has a single exemption of €10,000 covering all three, and it exists only on the annual tax return. No broker can apply it, because no broker knows how much of it the others have already consumed.
Losses offset gains, but only through the return. A loss realized at one broker offsets a gain realized at another. That offsetting does not happen automatically between platforms — it is claimed on the return. On the current reading, which our source rules still flag as needing verification, the offset works only within the same calendar year, with no carry-forward of losses into a later year. That point is worth confirming with the FPS Finance or your accountant.
Tax withheld is not a final settlement. A Belgian intermediary withholding 10% at source does so on the transactions it settled, without sight of your exemption or of losses realized elsewhere. The withheld amount is a payment on account. The difference between it and the tax actually due is recovered — or topped up — through the return.
A short illustration. Gains of €7,000 realized at a Belgian broker, which withholds €700. Losses of €3,000 realized at a foreign broker in the same year. The net result is €4,000, comfortably inside the exemption, so the tax due on those transactions is nil and the €700 is recoverable. Neither broker will ever compute that figure, because neither of them can see both halves.
What "consolidated" has to mean
A consolidated record is not a list of end-of-year balances. The return is computed from disposals, and a disposal only makes sense next to its acquisition. So, per broker and across the entire holding period:
- purchases: date, quantity, price, currency;
- disposals: date, quantity, proceeds, currency, and which parcel was sold;
- the 31 December 2025 closing value for anything held before 2026, since that is the acquisition value the step-up rule uses;
- tax already withheld, per broker and per type;
- dividends received and the withholding applied to each.
Three practical traps sit inside that list.
The one-year export. An export covering only the current tax year contains disposals whose matching purchases are in an earlier file. Without the purchase, neither the gain nor the holding period can be established.
Currencies. Positions bought and sold in dollars still have to end up as euro figures. Belfolio converts each row at the ECB reference rate for that row's own transaction date and keeps the rate used, so every converted amount can be traced back rather than reconstructed from a single year-end rate.
Acquisition dates. A missing date does not merely blur the record. It removes any possibility of demonstrating the ten-year exemption on a long-held parcel.
What the return is for
Read together, these points make the return the only place where the picture is complete. It is where the €10,000 exemption is claimed, where losses at one broker meet gains at another, and where tax withheld at source is reconciled against tax actually due.
Everything upstream of it — statements, exports, withholding lines — is input. None of it is a conclusion, and none of it is complete on its own.
Belfolio exists to assemble that input into one cross-broker record, name the positions it could not price or date rather than quietly filling the gaps, and show line by line how each figure was reached.
Always verify your figures
Belfolio computes and presents these amounts for information only. This is not tax advice. Verify them with the FPS Finance or your accountant before filing.
Published 16 Jul 2026