How to File a Patent in Belgium: 3 Proven Routes (2026)

Belgium sits at the administrative heart of the European Union and hosts a dense cluster of chemicals, pharmaceuticals, life sciences and logistics companies, which makes it a jurisdiction serious filers rarely skip. Its patent system, though, has one feature that quietly derails foreign applicants: Belgium has closed the direct national phase for international applications. If you are working out how to file a patent in Belgium, you have three genuine routes — a national filing at the Belgian office, validation of a granted European patent, or the European regional phase of a PCT application. This guide walks through each route, the mandatory search report the EPO prepares, the deadlines you cannot miss, and how a Belgian patent is enforced.

How to File a Patent in Belgium: The Three Routes

There is no single door into the Belgian system, and the right one depends on where else you want protection. The choice is best settled before any fee is paid, because switching routes later usually means starting over.

1. National route: file directly at the Belgian Office for Intellectual Property (part of the FPS Economy) for protection in Belgium only.
2. European route: obtain a European patent from the EPO; because Belgium is a party to the London Agreement, it takes effect in Belgium with no translation required.
3. Euro-PCT route: enter the European regional phase of a PCT application at the EPO — Belgium has no direct national phase, so this is the only PCT path in.

Whichever door you use, the substance is the same: a Belgian patent runs for a maximum of 20 years from its filing date, subject to annual maintenance fees, and is enforced through the Brussels courts and, for European patents, potentially through the Unified Patent Court. Belgium is a founding member of both the European Patent Convention and the UPC — a combination that shapes every route below.

Filing a National Patent at the Belgian Office

A national application is filed with the Belgian Office for Intellectual Property in one of the country’s official languages — French, Dutch or German — and must contain a request, a description, one or more claims, any drawings and an abstract. Applicants without a place of business in the European Economic Area must act through a professional representative.

Here is the point most foreign applicants miss. Belgium does not carry out a full substantive examination of novelty and inventive step the way the EPO does. Instead, a mandatory search report — drawn up by the European Patent Office on Belgium’s behalf, with a written opinion on patentability — accompanies the application, and the patent is granted on that basis. That places real weight on the applicant to read the opinion honestly, because a granted Belgian patent has not survived the adversarial scrutiny an examined patent has.

Grant typically follows within about 18 to 27 months. Annual maintenance fees (annuities) are payable to keep the patent alive and rise over its term; letting one lapse is one of the quietest ways a Belgian patent dies. The old, unexamined six-year short patent was abolished in 2014, so the search report is now unavoidable.

Reaching Belgium Through a European Patent

Most foreign applicants reach Belgium not through a national filing but by way of a European patent. Once the EPO grants and Belgium is designated, the patent takes effect in Belgium automatically. Belgium is a full party to the London Agreement and has dispensed with translation entirely, so — unlike Spain or Italy — there is no Belgian translation to file and no per-country validation fee to budget. It is one of the cheapest EPC states to hold a European patent in.

Since 1 June 2023 there is also the unitary patent: a single right covering the participating UPC states, including Belgium, obtained by a request for unitary effect within one month of grant. It removes per-country steps for those states but commits the patent to the UPC for its whole life, with no opt-out. If you are weighing that trade-off, our guide to filing a patent in France covers the same unitary decision in another core UPC jurisdiction.

Why Belgium Has No Direct PCT National Phase

This is the trap that catches the most filers. Belgium is one of a group of EU states — alongside the Netherlands, Italy, France, Ireland and others — that have closed the national route for PCT applications. The WIPO PCT Applicant’s Guide is blunt about it: the Belgian office closed the national route, and applicants must instead use the European regional phase. There is no direct Belgian national phase to enter.

In practice that means an international application reaches Belgium only through the EPO: you enter the European regional phase within 31 months of the earliest priority date, prosecute to grant as a European patent, and the patent then takes effect in Belgium. Diarising a phantom “Belgian national phase” deadline is a real and recurring mistake.

The one exception is the Paris Convention. If you are not using the PCT, you can still file a national Belgian application directly within 12 months of your first filing abroad. But once an application is in the PCT system, the European regional phase is the way in. You can confirm the position yourself in the official WIPO PCT Applicant’s Guide for Belgium.

Costs, Deadlines and Common Mistakes

The cost of filing a patent in Belgium depends almost entirely on the route. A national filing is comparatively inexpensive, and because Belgium waived translation, holding a European patent here avoids the translation bills that Spain and Italy still impose. The larger costs sit at the EPO for the European and unitary routes, and in annuities over the life of the patent.

• Priority: claim Paris Convention priority within 12 months of your first filing.
• Euro-PCT regional phase: 31 months from priority at the EPO — there is no direct Belgian national phase.
• European patent effect in Belgium: automatic on grant, with no translation required.
• Unitary effect: request within one month of grant if you want a unitary patent covering Belgium.
• Annuities: due annually and rising over the 20-year term.

The mistakes we see most often are assuming a direct PCT national phase exists in Belgium, treating the EPO search report as a full grant of validity, and missing the one-month window to request unitary effect. A short jurisdictional check at the outset avoids all three.

How a Belgian Patent Is Enforced

National Belgian patents are enforced before the Brussels Enterprise Court (tribunal de l’entreprise / ondernemingsrechtbank), which holds exclusive national jurisdiction over patent disputes — infringement, validity and preliminary measures alike. Belgium’s courts are experienced with cross-border matters and can order a descriptive seizure (saisie-description) to secure evidence of infringement, a powerful and distinctively Belgian remedy.

For European and unitary patents, the Unified Patent Court also reaches Belgium, which hosts a UPC local division in Brussels. If you are litigating locally, our specialists handle patent invalidation in Brussels and Antwerp, and the broader Belgium services hub maps the full offering.

Filing strategy in Belgium therefore cannot be separated from enforcement strategy: the unitary route buys breadth but locks you into the UPC, while a classic European patent kept out of the unitary system preserves the opt-out and keeps disputes before the Brussels court. Compare the approach with our guide to filing a patent in Italy, which — unlike Belgium — reopened its direct PCT national phase in 2020.

File in Belgium With Confidence

Choosing the right route into Belgium — national, European, unitary or Euro-PCT — and hitting every deadline is where foreign filings succeed or quietly fail. PerspireIP’s patent team handles Belgian national filings, European patent strategy and regional-phase entry, and prepares the prior-art and invalidity searches that decide enforcement. Contact us to map your Belgian filing strategy.

Frequently Asked Questions