Which tax documents should you keep after selling a property?

After a sale it is tempting to bin the paperwork, but several documents keep their value long after the deed. They fall into two groups: proof of what you paid and spent (which supports any capital-gain calculation and future disputes), and records of taxes and obligations (which the administration may still query). Getting the retention period right protects you if questions arise later.

The general rule in Belgium is that you keep the books, documents and vouchers needed to establish your taxable income for 7 years, and the tax administration recommends holding them for 10 years as a precaution, given periodic proposals to extend the standard period (Dirigeance, 2026). Documents linked to building works that fall under a quinquennial review are kept longer, up to 15 years (Dirigeance, 2026). Because a taxable property capital gain looks back at your acquisition value, renovation costs and selling costs, the underlying invoices should survive at least as long as any window in which a gain could be assessed.

The notarial deeds deserve special treatment. Your original purchase deed and sale deed establish ownership history, price and dates, and they are worth keeping indefinitely; the notary also retains an official copy, but your own set is invaluable for future tax, inheritance or dispute questions. Alongside them, hold the EPC and electrical certificates, the mortgage-release act, agency invoices, and each year's property tax assessment up to the sale.

The counter-intuitive lesson is that the papers you are most likely to discard, contractor invoices and the agency commission receipt, are exactly the ones that can save you tax later, because they lift your acquisition value and cut a taxable gain. A simple property file, kept digitally and on paper, costs nothing to maintain and can be worth thousands if a gain is ever assessed or an estate is settled.

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