Anyone seeking protection for an invention in Belgium has two routes: a European patent designating Belgium, or a national Belgian patent. The national procedure is remarkably lean by international standards – and differs from the German or European route in one decisive respect: the Belgian office grants the patent without substantive examination of patentability. This article walks through the procedure, the formal requirements, the fees, the language regime, and a few practical points worth keeping in mind.
The office and the legal basis
The competent authority is the Belgian Office for Intellectual Property – Office de la Propriété Intellectuelle (OPRI) / Dienst voor de Intellectuele Eigendom (DIE) – part of the Federal Public Service Economy (FPS Economy / SPF Economie), based in Brussels. The legal framework is essentially Book XI of the Belgian Code of Economic Law (Code de droit économique), together with the Royal Decree of 2 December 1986. As is standard, the maximum term is 20 years from the filing date.
The guiding principle: grant without substantive examination
The defining feature of the Belgian system is that the patent is granted irrespective of the search result. A novelty search is carried out (see below), but the office does not examine patentability on the merits and will not refuse grant even where the search indicates that the invention may lack novelty or inventive step. By express statutory wording, the patent is granted without any guarantee and at the applicant’s own risk.
The practical consequence: the validity of a Belgian patent is decided, if challenged, by the courts alone. Unlike a European patent – which is regarded as a “strong”, examined right – mere grant in Belgium says nothing about whether the patent will hold up. A Belgian patent issued with an unfavourable search report is therefore not automatically worthless: the search report binds neither the office nor the court.
Filing and formal requirements
Applications are filed with the OPRI using an application form – in person, by post, by fax, or electronically via the Benelux Patent Platform (BPP). To secure a filing date, three elements suffice initially: an explicit or implicit indication that the documents are intended to constitute a patent application; information identifying the applicant and allowing the office to make contact; and a part that, at first sight, appears to be a description of the invention.
Once a filing date has been accorded, the application must contain:
- a request for grant addressed to the competent Minister;
- the applicant’s identification details;
- a description of the invention, sufficiently clear and complete for a skilled person in the relevant field to carry it out;
- one or more claims defining the scope of protection;
- any drawings referred to in the description or claims;
- an abstract;
- where known, an indication of the geographical origin of any biological material from which the invention was developed;
- the designation of the inventor (or the inventor’s request not to be named).
The pages of the application must be numbered in accordance with the OPRI circular of 13 August 2020. Proof of payment of the filing fee must reach the OPRI within one month of filing.
Regularisation: if the conditions for the filing date or other requirements are not met, the OPRI invites the applicant to remedy the deficiency. The period is three months from notification, and a regularisation fee of EUR 60 must be paid within the same period. If the application is not regularised in time, it is deemed withdrawn (or deemed not to have been filed). The applicant may also cure deficiencies on its own initiative for as long as the patent has not yet been granted.
Language regime
Belgium has three national languages – Dutch, French and German – and the procedure follows the coordinated laws on the use of languages in administrative matters. This means that the language of the proceedings and of the correspondence is determined by the language the applicant (or the person represented, even where a representative acts) must use under those administrative-language rules. In practice it is therefore driven largely by regional allocation rather than freely chosen.
Two practical points matter:
- For the accordance of a filing date, the indication that the documents constitute a patent application and the identification details must be drafted in the prescribed national language.
- The part appearing to be the description, by contrast, may be filed in any language (for example English), provided a translation into the prescribed national language is supplied within three months of receipt.
The novelty search by the EPO
The search fee must be paid within 13 months of the filing date (or the priority date). The search itself is carried out by the European Patent Office, which produces a novelty search report together with a written opinion on patentability. Neither the report nor the opinion is binding, and neither guarantees validity.
On the basis of the report, the applicant may:
- withdraw the application;
- amend the claims, abstract and, if necessary, the description (without extending the subject-matter beyond the original disclosure); or
- keep the application as filed.
The applicant may also file written comments on the opinion for the record. The EPO does not, however, issue a revised report. The search report, the written opinion, any amendments and any comments all become part of the publicly accessible patent file.
Unity of invention / divisional applications: if the search report finds a lack of unity, it is drawn up for the invention mentioned first in the claims. Before grant, the applicant must then either limit the application or file one or more divisional applications (each carrying its own filing and search fees and any annual fees). Divisional applications retain the filing date and, where applicable, the priority date of the parent.
Publication and grant
The application is made available to the public 18 months after the filing or priority date. Once all formalities are complete and the fees due have been paid, the patent is granted by ministerial decree – as soon as possible after the 18-month period expires. On request, grant can be accelerated provided all formalities are in order; this can be useful where infringement threatens shortly after filing.
The patent is entered in the Belgian online patent register (eRegister) and published in summary form in the Recueil des Brevets d’invention. It takes effect when made available to the public. Before publication, provisional protection applies, determined by the published – or most recently filed – claims.
Fees
The national procedure is light on fees: there is no examination fee and no separate grant or publication fee. The figures below reflect the OPRI tariff as of 13 January 2026.
| Fee | Amount | Deadline |
|---|---|---|
| Filing fee | EUR 50 | within 1 month of filing |
| Surcharge for late payment of the filing fee | EUR 25 | within 3 months of the invitation to pay |
| Correction/addition of a priority claim | EUR 50 | on filing the request |
| Search fee (EPO novelty search) | EUR 300 | at the latest 13 months from filing/priority |
| Regularisation of an application | EUR 60 | within 3 months of the deficiency notice |
| Correction of errors of expression/transcription | EUR 35 | on filing the request |
| Restoration (application/patent, or priority right) | EUR 350 each | with the request |
| Validation of a European patent in Belgium | – | currently no validation fee |
Annual fees fall due from the third patent year, on the last day of the month corresponding to the anniversary of the filing date. They rise progressively:
| Year | EUR | Year | EUR | Year | EUR |
|---|---|---|---|---|---|
| 3 | 40 | 9 | 165 | 15 | 360 |
| 4 | 55 | 10 | 185 | 16 | 400 |
| 5 | 75 | 11 | 215 | 17 | 450 |
| 6 | 95 | 12 | 240 | 18 | 500 |
| 7 | 110 | 13 | 275 | 19 | 555 |
| 8 | 135 | 14 | 320 | 20 | 600 |
If an annual fee is not paid on time, a six-month grace period applies against a surcharge (EUR 85 for the 3rd–10th annuity, EUR 230 for the 11th–20th). If payment is still not made, the rights lapse – with effect from the original due date.
The annual fees also apply to European patents validated in Belgium (without unitary effect). Annual fees for unitary patents, by contrast, are paid directly to the EPO and are not collected by the OPRI.
What else to keep in mind
Validation of European patents – no translation required. Since 1 January 2017, Belgium no longer requires a translation of the specification to validate a European patent granted (or maintained as amended after opposition, or limited) in English, French or German – the relevant trigger being publication of the mention of grant on or after that date. A translation of the claims remains relevant for establishing provisional protection of a still-pending EP application. No validation fee is currently charged.
Unitary patent and the Unified Patent Court. Belgium participates in the European patent with unitary effect; the Unified Patent Court (UPC) has been operational since 1 June 2023, with a local division in Brussels. Annual fees for unitary patents are paid solely to the EPO.
Abolition of the short-term patent. Belgium’s former short-term patent (a six-year right without a search) was abolished when Book XI of the Code of Economic Law entered into force on 22 September 2014. Only the regular patent, with a mandatory search, remains.
PCT. Since 1 April 2018, the OPRI no longer acts as a receiving office for international applications under the PCT. The corresponding procedural fees are paid directly to the competent receiving office.
Representation. Applicants without a domicile or establishment in the European Economic Area must act through a representative registered with the OPRI (mandataire agréé). More generally, appointing an address for service is advisable so that the office can reliably reach the applicant.
Re-establishment of rights. Where an applicant or proprietor misses a time limit, a restoration procedure is in principle available. It is, however, excluded for certain deadlines – among them the period for regularising an application and certain annual fees arising from a restoration.
A Belgian patent as a first filing. The national patent works well as a priority-founding first filing: it can serve as the basis for claiming priority in other countries within twelve months. That makes it attractive even for applicants who initially have only the Belgian market in view, or who want to secure a priority date inexpensively.
Takeaway
A Belgian patent is quick and inexpensive to obtain: low official fees, no examination fee and no grant fee, a clearly timed procedure with the search handled by the EPO, and grant typically around 18 months after filing. The price of that leanness is the absence of substantive examination – the robustness of the right only becomes apparent if it is challenged in court. Applicants choosing the national route should therefore take the EPO’s search report and written opinion seriously and amend the claims, where sensible, before grant.
Photo: © OliBac, [CC BY 2.0]
