European patent validation

What validation is, and when it happens

During prosecution the application covers all EPC states for one designation fee. At grant, the patent splits. Article 65(1) EPC lets each state whose official language is not the language of the patent demand a translation, filed at its office within 3 months of the date the mention of grant is published, or a longer period if the state allows one. The state may also charge for publishing the translation (Art. 65(2)) and may treat the patent as void from the start if the requirements are missed (Art. 65(3)). Greece and Hungary say so expressly in their national law.

The clock starts on the publication date of the mention of grant, not the date of the decision to grant, which comes earlier. Many states also require a local representative or address for service for proprietors based outside the EEA or the state itself. The same steps apply again if the patent is later amended in opposition or limitation: most states then want a translation of the amended text, on a fresh 3-month clock.

The London Agreement

The London Agreement on the application of Article 65 EPC entered into force on 1 May 2008. Its 23 states (counting Switzerland and Liechtenstein separately) waive most translations:

• States sharing a language with the EPO require no translation at all (Art. 1(1)): Belgium, France, Germany, Ireland, Liechtenstein, Luxembourg, Monaco, Switzerland, United Kingdom.
• Other states can require the claims in their own language (Art. 1(3)) and can prescribe one EPO language for the rest (Art. 1(2)). Albania, Croatia, Denmark, Finland, Hungary, Iceland, the Netherlands, Norway and Sweden have prescribed English, so a patent granted in English needs only the claims translated. Latvia, Lithuania, North Macedonia and Slovenia have prescribed no language and ask for the claims only.
• Montenegro is the latest to join, from 1 August 2025. It asks for the claims in Montenegrin with the specification in English.

The Agreement applies to patents whose grant was mentioned after it took effect in the state concerned. For Albania, Lithuania and North Macedonia, the EPO notes it made no difference, because their rules already matched.

Validation requirements in the EPC states

The table assumes the patent was granted in English, by far the most common language of proceedings. "Full translation" means the description, the claims and any text in the drawings. Deadlines run from the publication of the mention of grant. "UP" marks the 18 states covered by a Unitary Patent registered today.

• Spain: the translation publication fee is €278.28 plus €11.19 for each page over 22 when filed electronically, according to the 2026 tables. A proprietor based outside Spain must have the translation made by an OEPM-accredited patent attorney, a sworn translator or another qualified professional.
• Italy: if a request for unitary effect is rejected or withdrawn, the 3 months run from that event instead. Sweden has the same rule for a rejected request.
• Patents granted in French or German: the "no translation" states still need nothing. The claims-only states then also want a translation of the rest, usually into English or the national language, as noted in the table.

Extension and validation states

Some states outside the EPC have agreed to recognise European patents under their own national law: the older extension agreements (1993 to 2009) and the validation agreements (since 2010). The choice here is made before grant, not after. Every application is deemed to request extension or validation for each state whose agreement was in force on its filing date, and the request lapses unless you pay that state's fee to the EPO within 6 months of the mention of the search report (EPO). Late payment is possible within a further 2 months with a 50% surcharge. Re-establishment of rights is not.

• Montenegro was an extension state until it joined the EPC on 1 October 2022. Extension (fee €102) remains possible only for applications filed before that date.
• Republic of Moldova was a validation state from 1 November 2015 and joined the EPC on 1 June 2026. Applications filed from that date designate it like any other member state. For applications filed before it, and their divisionals, validation still applies: fee €200, then a Romanian translation of the specification filed with AGEPI within 3 months of grant.
• Lao PDR is the newest, for applications filed from 1 April 2025. A Lao translation of the claims and a publication fee go to the Department of Intellectual Property within 3 months of grant, and renewal fees are paid there, not to the EPO (OJ EPO 2025, A23).
• Not yet in force: validation agreements with Costa Rica (signed 13 December 2024) and Angola (signed 23 June 2026).

Table IV lists a local representative as required for the post-grant step in each of these states, at least for proprietors based abroad. Lao PDR is not yet in the table.

How validation interacts with the Unitary Patent

Since 1 June 2023 the proprietor can ask the EPO, within 1 month of the mention of grant, to register unitary effect. A Unitary Patent covers 18 EU states in one go: Austria, Belgium, Bulgaria, Denmark, Estonia, Finland, France, Germany, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Portugal, Romania, Slovenia, Sweden. No national validation is needed in those states. During the transitional period the request needs one full translation instead: into any other official EU language if the patent is in English, or into English if it is in French or German. Our Unitary Patent guide covers the request, the renewal fees and the court.

Everything outside those 18 states still needs classic validation: the UK, Switzerland, Ireland, Spain, Poland, Türkiye, Norway, the Czech Republic and the rest of the table. The practical consequences:

• Decide early. The 1-month unitary deadline comes before the 3-month national ones, and it cannot be extended. Plan the whole post-grant map when the Rule 71(3) communication arrives.
• All-or-nothing in the UP states. You cannot take unitary effect for some participating states and validate others nationally. If you want only Germany and France, classic validation is the cheaper route: no translation is needed in either.
• If unitary effect is refused. Italy and Sweden restart their 3-month validation period from the rejection, so you can fall back to national validation there. Check other states' rules if the request is at risk.
• Fixed territory. A Unitary Patent covers the states participating on the day it is registered and never grows. Ireland, for example, can only be covered by classic validation, which needs no translation.

A validation checklist

1. Before the 6-month search report deadline, decide whether to pay any extension or validation fees. This is the only chance.
2. At the Rule 71(3) communication, list the target countries and split them into Unitary Patent states and the rest.
3. Within 1 month of the mention of grant, file the request for unitary effect with its translation, if you want one.
4. Within 3 months (check the table for exceptions), file the national translations and pay publication fees through local representatives where required.
5. Diary the national renewal fees, which start with the year after the year of grant, and the Unitary Patent renewal fee, which is paid to the EPO.

For what all of this adds up to, with the EPO's own cost estimates and worked examples, see how much a European patent costs. The fees paid to the EPO itself are listed in our EPO fees 2026 table. If Germany is your main market, you can also file there directly: see the German patent application guide.

More EPO guides

• How to file a European patent application

  Direct or Euro-PCT filing, search, examination, grant and validation, with the EPO fees in force from 1 April 2026.

• Patent drawing requirements: USPTO, EPO and India

  37 CFR 1.84, the EPO rules that replaced Rule 46 EPC, and Indian rule 15, compared side by side.

• How to write patent claims: USPTO, EPO and India

  Claim structure and worked examples, then the claim rules and fees at the USPTO, the EPO and the Indian Patent Office, side by side.

• The Unitary Patent and the UPC, explained

  The 18 countries covered, renewal fees, the UPC opt-out, and when classic validation is the better choice.

• EPO fees 2026: the full fee schedule

  Every EPO fee in force from 1 April 2026, the 30% micro-entity reduction, PCT fees at the EPO and a fee calculator.

• How much does a European patent cost?

  EPO fees to grant, translations, validation and renewals, with the EPO's Unitary Patent cost comparison and two worked examples.

• The problem-solution approach to inventive step at the EPO

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• Software and AI patents in Europe

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• European patent opposition at the EPO

  The 9-month deadline and fee, the grounds, procedure and oral proceedings, appeal to the Boards, and how it compares with UPC revocation.

• Supplementary protection certificates (SPCs) in Europe

  Who can get an SPC, how long it lasts, the filing deadline, the paediatric extension, the manufacturing waiver and the unitary SPC proposal.

• The European search report and EESR, explained

  X, Y and A citation categories, the search opinion, Rule 62a and 63 limited searches, and the Rule 70a deadline to reply.

• Entering the European phase from a PCT application

  The 31-month deadline, Rule 159 acts and fees, the supplementary search, Rule 161, translations and a worked example.

• European divisional applications under Rule 36 EPC

  When the parent is pending, fees by generation, back renewal fees, the Article 76 added-matter trap and timing.

• How to speed up EPO prosecution: PACE, PPH and waivers

  PACE since February 2026, the Rule 70(2) and Rule 161 waivers, PPH with the USPTO, and fast Rule 71(3) approval.

• The European Patent Convention, annotated

  Key EPC Articles and Rules explained one by one, from novelty and claims to Rule 71(3), with deadlines, fees and Enlarged Board case law.

• Types of patent searches, and which one you need

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• Freedom-to-operate search in the US and Europe

  In-force claims only, legal status checks at the USPTO, EPO and UPC, FTO opinions after Halo, and design-arounds.

• Invalidity search: prior art to challenge a patent

  IPR, PGR, EPO opposition and UPC revocation deadlines, prior art dates, standards documents and claim charts.

• Patent landscape analysis, step by step

  Building a CPC and keyword dataset, cleaning families and names, the metrics that matter and the 18-month publication lag.

• How to search Espacenet

  Smart and Advanced search, field identifiers, proximity and truncation, CPC, INPADOC families, legal events and Global Dossier.

• Google Patents search guide

  Search operators and fields, Boolean and proximity syntax, non-patent literature, and where Google Patents falls short of the official databases.

• The Cooperative Patent Classification (CPC), explained

  How CPC symbols are built, CPC against IPC, the Y section, how to find the right class and how to search it in each database.

• Patent search Boolean operators and search strings

  Boolean, proximity and truncation syntax compared across Patent Public Search, Espacenet, Google Patents and The Lens, with semantic search for contrast.

• The PCT application: timeline, fees and national phase

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• How much does a patent cost?

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• How long does a patent last?

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• Can AI write a patent application?

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