Entering the European regional phase from a PCT application

The 31-month deadline

Rule 159(1) EPC sets 31 months from the international filing date or, where priority is claimed, from the earliest priority date. Month periods end on the same day number in the later month, or on the last day of that month if it has no such day (Rule 131(4)). A priority date of 31 March gives a deadline of 31 October two years later; 30 July gives 28 February (or 29 in a leap year). If the last day falls on a day the EPO filing offices are closed, the period runs to the next working day (Rule 134(1)).

Entry is not one act but a set of independent ones, each with its own consequence (Guidelines A-XII, 4.3). The EPO strongly recommends filing EPO Form 1200, which lists every act, has the examination request preselected, and earns the lower online filing fee when filed online. You can enter early: an express request for early processing (Articles 23(2) and 40(2) PCT) starts the European phase as soon as the requirements are met as if the 31 months had expired that day.

Applicants without a residence or place of business in an EPC state, such as US, Indian or Japanese companies, must appoint a European patent attorney for the European phase (Article 133(2) EPC). Up to the 31-month date they may still file Form 1200, translations and amendments themselves; after it, everything except paying fees must go through the representative (Guidelines A-XII, 6.2).

Rule 159 acts and fees

The designation fee and examination request fall due at 31 months only if their normal periods (6 months from the publication of the international search report) have already expired. Unless the international search report was published later than 25 months from priority, they have, so in practice both are paid at entry (Guidelines C-II, 1.2).

The 3rd-year renewal fee is counted from the international filing date, not the priority date. Where the PCT application was filed 12 months after priority, it falls due well after 31 months, so it is rarely paid at entry. If the EPO drew up the international preliminary examination report, the examination fee is reduced by 75% (Article 14(2) of the Rules relating to Fees), as long as the subject-matter to be examined was covered by that report.

Some requirements are "further" requirements rather than minimum ones: designating the inventor, the priority document, a standard sequence listing, appointing a representative, and copies of earlier search results under Rule 141. Missing them at 31 months does not stop entry, but the EPO will invite you to fix them and may delay the search until you do (A-XII, 4.4).

The supplementary European search, and when it is dispensed with

The international search report takes the place of the European search report (Article 153(6)), but the EPO still draws up a supplementary European search report under Article 153(7), with its own search opinion, unless the Administrative Council has dispensed with it (Guidelines B-II, 4.3.1):

• EPO was the ISA or the supplementary ISA: no supplementary search, no search fee, and the examination fee is €2,240. The file goes straight to the examining division once the formalities are done.
• Austrian, Finnish, Spanish, Swedish or Turkish office, Nordic Patent Institute or Visegrad Patent Institute was the ISA: a supplementary search is done but its fee is reduced by €1,365, to €230, for international applications filed up to 31 March 2028 (CA/D 9/25, Article 3).
• Any other ISA, such as the USPTO, JPO, CNIPA, KIPO or the Indian Patent Office: full supplementary search, €1,595 search fee and €2,010 examination fee.

The supplementary search is based on the claims on file when the Rule 161(2) period ends. If the EPO finds the claims lack unity, it searches the first invention and invites further search fees for the others within 2 months (Rule 164(1)). A supplementary report may cite no new documents at all ("No further relevant documents disclosed"), with the opinion relying on the international citations. See our guide to reading the European search report for the citation categories and how to answer the opinion.

Where there is no supplementary search and the claims you want examined cover an invention the EPO did not search as ISA, the examining division asks for a further search fee before it will examine it (Rule 164(2)).

The Rule 161/162 communication, briefly

Promptly after the 31 months expire, the EPO sends a combined communication under Rules 161 and 162. Its effect depends on who searched:

• EPO was ISA (Rule 161(1)). You have 6 months, not extendable, to respond to a negative written opinion, supplementary international search report or IPER by amending or commenting. No response means deemed withdrawal, unless amendments or comments filed at entry already count as one. The form of the communication tells you whether a reply is mandatory.
• EPO was not ISA (Rule 161(2)). You may amend the application once within 6 months, and the supplementary search is based on the amended claims. A reply is optional.

In both cases unpaid claims fees can still be paid in the same 6 months, calculated on the claims on file at its end; an unpaid claim is deemed abandoned (Rule 162(2) and (4)). You can skip the 6-month wait altogether by waiving the communication in section 6.4 of Form 1200, provided you also pay all claims fees and, where the EPO was ISA, reply to its opinion at entry (OJ EPO 2015, A94). More on that in our guide to speeding up EPO prosecution.

A practical point: file the claims you want in Europe at entry rather than waiting for the communication. Most PCT claim sets need work for the EPO anyway (two-part form, one independent claim per category, no omnibus claims), and the claims fees are counted on what you file.

Translations

A translation is needed only if WIPO published the international application in a language other than English, French or German, for example Japanese, Chinese, Korean or Spanish (Guidelines A-XIII, 3). The language you translate into becomes the language of the proceedings. If the application was published in an EPO language, a translation is neither needed nor accepted, and you cannot switch language (G 4/08).

When the EPO acts as designated Office, the translation covers the description and claims as filed, any text in the drawings, the abstract as published, any published rectification, and language-dependent free text in a sequence listing. Article 19 amendments need translating only if you want to proceed on them. When the EPO acts as elected Office (a Chapter II demand was filed), you must also translate the annexes to the IPER, whether or not you proceed on them (A-XIII, 3.1).

Euro-PCT deadlines at a glance

Periods triggered by an EPO communication run from the date the communication bears (Rules 126(2) and 127(2)). The 6-month supplementary search target is the EPO's own commitment, not a legal deadline (OJ EPO 2025, A69).

Worked example

A US start-up files a US provisional application on 9 April 2025 and a PCT application on 8 April 2026, in English, with the USPTO as receiving Office and ISA. The PCT has 20 claims and 30 pages.

• 31-month deadline: 9 April 2025 + 31 months = 9 November 2027, a Tuesday.
• Due by then: filing fee €135, search fee €1,595 (USPTO was ISA, so there is a supplementary search), designation fee €720 and examination fee €2,010, because the international search report was published with the application around 18 months from priority and the 6-month periods ran out in 2027. Five claims over 15 add €1,450. Total: €5,910. No translation is needed.
• 3rd-year renewal: counted from the international filing date of 8 April 2026, so it falls due on 30 April 2028, after entry. It is €725.
• Rule 161(2): if the communication is dated 3 December 2027, the one chance to amend before the supplementary search ends on 3 June 2028. Had the applicant filed EPO-style claims, paid the claims fees and waived the communication at entry, the search could start straight away.
• Supplementary search: the EPO aims to issue it within 6 months of the end of the Rule 161(2) period, so by about December 2028 here. The Rule 70(2) communication follows, with 6 months to confirm examination and answer the search opinion.

Had the applicant chosen the EPO as ISA, it would have paid €4,545 at entry (€135 + €720 + €2,240 + €1,450), with no supplementary search, and would have had to answer the EPO's written opinion within 6 months of the Rule 161(1) communication if it was negative.

If you miss the 31 months

The application is deemed withdrawn (Rule 160(1)) and the EPO sends a communication under Rules 160(2) and 112(1). Within 2 months of it you can request further processing by completing each missed act and paying a fee for each one: 50% of a late fee, or €315 for a missed act such as the translation (Rule 135(1), RFees item 12). Missing several fees therefore means several further processing fees. After that, the only routes are re-establishment of rights under Article 122, or for the translation and filing fee, reinstatement under Rule 49.6 PCT. Both require showing all due care (Guidelines A-XIII, 3.3 and 9).

Once the application has entered the European phase, it is pending and you can file a European divisional application from it; you cannot divide a Euro-PCT application before entry. After grant, the European patent can be validated nationally or given unitary effect, exactly as for a direct filing. The full process is in our guide to the European patent application.

More EPO guides

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• The Unitary Patent and the UPC, explained

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• The European search report and EESR, explained

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• European divisional applications under Rule 36 EPC

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• Invalidity search: prior art to challenge a patent

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• Patent landscape analysis, step by step

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