Tax law · Property law · Law of evidence
Capital gains in 2026: evidence before the rate
The sale proceeds are not the same as your taxable gain. The starting value, the category of transaction and the supporting records can change the result.
Case status23 September 2026 edition · sources checked on 22 September.
01
An enacted reform, not a universal rate
This overview primarily concerns Belgian-resident individuals holding securities as part of their private assets. You sell securities. The proceeds appear in your account. Yet that amount does not tell you your taxable gain or what you will retain after tax. The decisive question is not simply: “What rate applies?” It is also: “What starting value can I establish?” This article concerns Belgian tax law.
The Act of 6 April 2026, published in the Belgian Official Gazette on 21 April, introduced a tax on capital gains on financial assets, taking effect from 1 January 2026. This is no longer merely a government announcement. However, the tax applying since January must be distinguished from the statutory withholding mechanism starting on 1 June, which is subject to transitional rules. [1]
02
Four distinctions that protect the calculation
Classify before calculating. The legislation distinguishes internal transfers, shareholdings of at least 20% and the ordinary regime. A private portfolio, a holding in your own company and a business asset are not interchangeable. A professional transaction or one outside the normal management of private assets requires a different analysis. “Ten per cent on everything” is therefore misleading. [1]
Establish the starting value. For assets acquired before 2026, the reference is generally their value on 31 December 2025: the last closing price of 2025 for listed securities, and specific statutory valuation methods for unlisted securities. Subject to the statutory conditions, a proven historical acquisition value may be relied upon for disposals up to 31 December 2030. This does not permit a free choice of valuation. [1]
Evidence genuinely matters. Without reliable evidence of the acquisition value, the proceeds received may constitute the taxable capital gain. A statement, subscription agreement or transaction history passed on with a gift is therefore more than an archive. For the products it describes, the Belgian Debt Agency stresses the importance of preserving these records when securities have been gifted, inherited or transferred. [1,2]
Separate withholding from the final tax. Under the ordinary regime, the annual exemption is €10,000 for 2026. Withholding by the intermediary does not take that exemption into account. Where withholding tax has been deducted, claiming the exemption requires a request for credit and, where applicable, a refund through the tax return, with supporting documents available. Losses cannot be offset without limits: they must concern the same taxpayer, the same taxable period and the same statutory category. [1,2]
03
The file to assemble before selling
- Locate purchase records, dates, quantities, currencies and statements showing values on 31 December 2025. For securities received from someone else, preserve the relevant history of the donor or deceased owner too.
- Bring together your 2026 transactions, gains and losses by category, withholding statements and certificates. Moving to another bank should not mean losing the records needed to establish your position.
- Before a substantial disposal, have the applicable regime, the connections between seller and buyer, and the valuation method reviewed. This checklist is neither a tax simulation nor advice to sell. It prepares the ground for an assessment tailored to your circumstances.
Value has a memory.
Locate the records establishing acquisition and its date.
Conceptual illustration created with AI assistance — not real data or an automated legal outcome.Sound tax preparation starts with a verifiable file, not a reassuring percentage.
