Disclaimer: This guide provides general information about United Kingdom patent translation requirements. It is not legal advice, does not determine the scope of any patent claim and does not replace instructions from a regulated UK patent attorney.

UK Patent Translation Requirements for Foreign-Language Applications and PCT Deadlines

UK patent translation requirements depend on what you are filing. A foreign-language description in a direct UK application, a non-English PCT publication, a priority document and an international-phase amendment do not share one deadline or one consequence. Treating them as a single “certified translation” task can lead to unnecessary expense, an incomplete national-phase file or the loss of a priority claim.

Key Takeaways

A direct UK application may receive a filing date even when its description is not in English or Welsh. UKIPO will normally require an English or Welsh description within two months of its notice.
A PCT application that was not published in English generally needs an English translation to enter the UK national phase, normally by 31 months from the priority date. Welsh is not an alternative for this PCT requirement.
A foreign-language priority document does not routinely need translating at filing. UKIPO may request a translation—or, in an appropriate case, a declaration of complete translation—if priority becomes material during examination.
UKIPO does not impose a blanket notarisation or pre-certification rule. Under Rule 115, evidence of accuracy may be requested if the Office has reasonable doubts about a translation.

Who This Guide Is For

This United Kingdom-wide guide is for overseas inventors, start-ups, foreign companies, patent paralegals and international IP teams preparing a direct UK application, entering the UK national phase of a PCT application, claiming priority from a foreign filing or handling non-English amendments.

Typical working language pairs include Chinese–English, Japanese–English, Korean–English, German–English, French–English, Spanish–English and Russian–English. UKIPO does not publish a reliable ranking of patent-translation language pairs, so these should be treated as common international filing combinations rather than official market statistics.

The usual file contains some combination of a description, claims, abstract, drawings with text, a certified copy of an earlier application, Article 19 amended claims, Article 34 amendments annexed to an international preliminary examination report, and later replacement pages. This guide is particularly useful when the team is unsure which version requires translation, whether the deadline runs from filing, priority or a UKIPO notice, or whether an ordinary professional translation needs a separate certificate.

UK Patent Translation Requirements by Filing Route

Document or route	Required language	When translation is triggered	Main consequence of non-compliance
Foreign-language description in a direct UK application	English or Welsh	Normally within two months after UKIPO issues its notice	The application may be refused
Application filed by reference to an earlier foreign application	English or Welsh translation if the certified copy is not in either language	Normally within four months of the UK filing date	The application may be treated as withdrawn
PCT application not published in English	English	Normally by 31 months from the priority date, with the national fee	The UK national phase may not begin; separate late-entry remedies may need consideration
Non-English Article 19 or Article 34 amendment	English	Normally by national-phase entry; a qualifying omission may produce a three-month UKIPO notice	The amendment may be disregarded
Foreign-language priority document	English or Welsh	Only if an examiner directs, usually during substantive examination	The affected priority claim may be disregarded
Another non-English document filed with UKIPO	Normally English, subject to the specific rule and exceptions	With the document or within a period directed by UKIPO	UKIPO may take no further action on that document

Direct UK Filing: A Foreign-Language Description Can Preserve the Filing Date

The first counterintuitive rule is that translation and filing date can be separated. A document that appears to be a description may be filed in another language and still help establish a UK filing date, provided the other minimum filing-date conditions are met. The indication that a patent is sought and the applicant’s identity or contact route must remain intelligible for the filing process.

Once UKIPO accords a filing date, it notifies the applicant that the application does not comply with the language requirement. The applicant normally has two months from that notice—not automatically two months from the filing date—to file a description in English or Welsh. Failure to respond may lead to refusal. This distinction is set out in the UKIPO Manual of Patent Practice, Section 14.

This route can be valuable when disclosure is urgent, but it should not be mistaken for permission to translate casually later. The translated description must faithfully support the claims. Introducing a feature that was not disclosed by the foreign-language text may create an added-matter problem that a polished certification statement cannot cure.

What the direct-filing translation should cover

The complete description, including headings, examples, tables, formula labels and sequence-related text where applicable;
claims and abstract if they were supplied in the foreign-language package or are being added to complete the application;
text embedded in drawings, not merely the drawing captions;
defined terms, reference numerals, units and abbreviations consistently across every component.

If the filing was made by reference to an earlier application instead of supplying a description, the certified copy—and an English or Welsh translation if that copy is in neither language—normally must substantiate the reference within four months of the UK filing date. The detailed filing-date treatment appears in UKIPO Manual of Patent Practice, Section 15. Applicants should have a patent attorney verify the deadline and any available extension rather than applying the ordinary two-month notice rule by analogy.

PCT UK National Phase: English Only and the 31-Month Control Point

A PCT application entering the UK national phase follows a narrower language rule. Where the international application was not published in English, an English translation is generally necessary. The normal national-phase deadline is 31 months from the priority date—or from the international filing date if there is no priority claim—and the national fee must also be dealt with.

The UKIPO’s Manual of Patent Practice, Section 89A explains both the 31-month framework and the required handling of non-English applications and amendments. A direct UK filing may use English or Welsh, but the necessary PCT national-phase translation is into English. This is a specifically British distinction that generic international-filing checklists often miss.

If WIPO has already published the international application in English and communicated it to UKIPO, a second full translation will usually be unnecessary. Before ordering anything, compare the PATENTSCOPE record with the versions the applicant intends to rely upon. The English publication may cover the original application while a later amendment, biological-material statement or annex remains in another language.

Build a version inventory before translation

Record the international application number, filing date and earliest priority date.
Download the published WO document and confirm its publication language.
Identify the description, claims, abstract and every item of text in the drawings.
Check for Article 19 amended claims and any accompanying statement.
Check the international preliminary examination report for Article 34 replacement sheets or annexes.
Mark which version should enter the UK national phase and which version is only historical.
Give the same inventory to the patent attorney and translation team.

The most damaging practical error is often not a mistranslated word but the translation of the wrong version. A filing team may translate the claims as originally filed while intending to rely on later international-phase claims. Page-by-page version control is therefore part of patent translation quality, not a separate administrative exercise.

What Happens When a PCT Amendment Translation Is Missing?

Missing an amendment translation does not always destroy the entire UK application. If the national fee and the necessary translation of the application have been filed by the 31-month point, but a required translation of an amendment is absent, UKIPO must notify the applicant of the missing translation and require it within three months from the date of the notice.

If the missing translation is not supplied in time, the relevant amendment may be disregarded. That can leave the application proceeding on an earlier text, which may be commercially very different from the claims the applicant expected to prosecute. Extensions and reinstatement questions are technical and fact-dependent; do not assume that a discretionary remedy will be available.

For translation preparation, send the translator the original application, every changed page and a clean comparison showing additions and deletions. A certified translation of only the final claim set may not explain how it corresponds to the PCT record.

Priority Documents: Do Not Translate Automatically

A certified copy of a foreign priority application and a certified translation are different things. The copy proves what was filed at the earlier patent office. The translation makes its contents accessible to UKIPO. Producing one does not automatically satisfy a requirement for the other.

UKIPO generally does not demand an English or Welsh translation of every foreign priority document when the later UK application is filed. Under Rule 9 practice, an examiner may request one when the earlier disclosure matters to the assessment of priority, particularly where novelty or inventive step turns on what the earlier application actually disclosed. The request normally arrives during substantive examination and specifies its own response period.

The UKIPO Formalities Manual, Chapter 6 also permits an appropriate declaration that the UK application is a complete translation of the priority document. A declaration may identify minor differences rather than pretending two texts are identical. It can be signed by the applicant or agent. If neither the requested translation nor an acceptable declaration is filed in time, the relevant priority claim may be disregarded.

This is why ordering an urgent translation of every priority document at filing can be wasteful. First confirm whether UKIPO has requested the translation, whether the later application really is a complete translation and whether differences between the two texts prevent use of a simple declaration.

Does UKIPO Require a Certified, Sworn or Notarised Translation?

UK patent rules focus on a complete and accurate translation, not a universal label such as “sworn translation.” There is no general UKIPO rule requiring every patent translation to be notarised, apostilled or prepared by an office-appointed translator. The rules also do not establish routine certification wording comparable to some immigration systems.

Applicants sometimes use “certified translation” as a practical bridge term for a translation supplied with the translator’s identity, qualifications, date, signature and accuracy statement. That can create a useful evidential record, but it does not replace the patent-specific question: does the English or Welsh text accurately reproduce the correct source version?

For a short explanation of the terminology, see CertOf’s guide to certified versus notarized translation. For patent-specific production issues, see certified translation of patent documents to English.

Rule 115: When UKIPO Can Ask for Evidence of Accuracy

Verification is not normally required in advance. However, if UKIPO has reasonable doubts about a filed translation, Rule 115 allows it to notify the person who supplied the translation, explain the doubt and require evidence establishing accuracy. If satisfactory evidence is not furnished, UKIPO may take no further action on the affected document. The official position appears in the Manual of Patent Practice, Section 123.

The rule does not prescribe one universal evidence package. The response must address the concern in the notice. Depending on the issue, the applicant and attorney may consider a signed translator statement, relevant qualifications and subject-matter experience, a second linguistic review, a source-to-target comparison, an explanation of a disputed term, or corrected pages with a precise change log. A generic stamp that never addresses the questioned wording may add little.

Self-translation is not subject to a simple statutory ban, but it creates evidential and drafting risks. The inventor may understand the technology yet unconsciously broaden or narrow a term. A family member or automated tool may produce readable prose while missing antecedent basis, claim dependency or a limiting technical distinction. UKIPO’s concern is the reliability of the filed text, not which software was used to produce a draft.

The Three Numbers That Matter More Than Market Estimates

Number	Meaning	Why it matters
2 months	Normal response period after notice for a foreign-language description in a direct UK filing	The clock generally begins with the UKIPO notice, so correspondence handling matters.
31 months	Normal UK national-phase point measured from priority, or filing if there is no priority	The translation team must work backward from this date and allow attorney review time.
3 months	Notice period in the qualifying missing-PCT-amendment situation	It is a limited correction window, not a general extension for an incomplete national-phase file.

There is no official UK tariff or promised turnaround time for private patent translation. Cost is affected by claim count, technical field, source quality, tables, formulas, drawing text, amendment history and the amount of independent review. Obtain a document-specific quote rather than relying on a generic per-page estimate.

How to Prepare and Submit the Translation in Practice

Identify the legal route. Mark the file as direct UK, filing by reference, PCT national phase, priority response or later amendment.
Confirm the controlling date. Use the priority data and the actual date of any UKIPO notice. Do not calculate a deadline from memory.
Freeze the source version. Give each description, claim set and amendment a date and version label.
Translate complete units. Preserve claim numbering, dependencies, reference numerals, formulas, tables and drawing labels.
Run technical and legal-linguistic review. Verify defined terms, negative limitations, ranges, units and every occurrence of a claim term.
Prepare evidence only to the required level. Add a signed accuracy statement when useful, but do not purchase notarisation or an apostille unless a specific recipient has requested it.
Have the filing professional approve the packet. Translation providers should not decide which claims to prosecute or whether an amendment adds matter.
Retain the submitted PDF and receipt. Keep the exact source, delivered translation and filed version together.

UK patent forms and pending-application documents can be submitted through official online services, with email, post and limited in-person alternatives available for specified filings. Postal documents receive the date they actually reach UKIPO, so ordinary mail should not be treated as a deadline guarantee.

Overseas applicants should also establish a valid address for service in the UK, Gibraltar or the Channel Islands. The Isle of Man is also accepted by UKIPO. For the foreign-applicant workflow and its exceptions, use CertOf’s UK patent and trade mark address-for-service guide. City-level filing logistics are separately covered in the London patent and trade mark filing guide.

Five Filing Failures This Workflow Is Designed to Prevent

Paying for an urgent priority-document translation before an examiner has requested it;
assuming that the direct-filing option of English or Welsh also applies to PCT national-phase translations;
translating the WO publication but overlooking Article 19 or Article 34 replacement pages;
responding to an accuracy concern with a generic certificate rather than evidence addressing the disputed wording;
allowing a UKIPO notice to sit between the foreign applicant, patent attorney and translation provider until most of the response period has passed.

A sound handoff should include the notice itself, the deadline confirmed by counsel, the source-language version, every amendment and the intended filing version. Sending only “the patent PDF” invites omissions.

Commercial Translation and Filing Support

UKIPO does not publish or endorse a list of approved patent translation companies. Compare providers by their published technical scope, review process and service boundary rather than by claims of official recognition.

Provider	Published service scope	Potential use	Boundary to confirm
CertOf	Online certified and document translation workflow, revision support and format-preserved delivery	Individual applications, priority documents, claims, amendments and review-ready accuracy packages	Document preparation only; not a UK patent attorney, filing agent or address for service
RWS	Describes filing-ready patent translation, technical specialisms and high-volume IP workflows	Large international portfolios and law-firm or corporate procurement programmes	Confirm which filing, deadline-management and local-agent functions are included in the engagement
Questel IP Services	Describes patent translation, foreign-filing coordination and IP portfolio services	Centralised multi-jurisdiction filing and translation management	Confirm the responsible UK representative and the exact translated deliverables

The commercial descriptions above come from the providers themselves and are not independent quality ratings or UKIPO endorsements. Ask each provider who performs technical review, how corrections are logged, whether claim dependencies and drawing text are checked, and what happens when the source version changes after translation begins.

For a CertOf order, upload the source file through the secure translation submission page. The guide to ordering a certified translation online explains the document workflow, while PDF, Word and paper delivery formats helps teams choose a reviewable master file.

Regulatory and Public Resources

Resource	Use it for	Cost and limitation
UK Intellectual Property Office	Official notices, filing records, procedural guidance and administrative questions	Guidance and enquiries are public; UKIPO does not give personalised patent strategy or recommend translators.
CIPA Find a Patent Attorney directory	Identifying patent attorneys and firms by practice or location	Directory access is free; inclusion is not a guarantee of fit for a particular technology or file.
Intellectual Property Regulation Board	Checking whether a patent attorney or firm is regulated and finding the relevant complaint route	Regulatory resource; it does not resolve ordinary translation-provider disputes.

Complaints and Misleading Patent Invoices

A disagreement about claim scope or the legal effect of a translation is not the same as an administrative-service complaint. Complaints about UKIPO mistakes, delay or staff service should follow the UKIPO complaints procedure. Concerns about a registered patent attorney should normally first be raised through that attorney or firm’s own complaint process; unresolved eligible concerns can then use the IPReg complaint form. A dispute with a translation company normally begins with the provider’s contract, correction policy and complaint procedure.

Patent applicants may also receive unsolicited invoices offering publication, registration, monitoring or other services that look official. UKIPO warns that such organisations are not associated with the Office and advises recipients not to pay before verifying the request. Suspicious invoices can be sent to [email protected] and reported through the routes listed in the official misleading-payment guidance. A demand for a “mandatory patent translation registration fee” should be checked against the UKIPO case record and the applicant’s patent attorney.

Frequently Asked Questions

Can a UK patent application initially be filed in a foreign language?

Yes. A foreign-language document that appears to be a description can help establish a filing date if the other minimum requirements are satisfied. UKIPO will then normally require an English or Welsh description within two months of its notice.

Can I use Welsh for a PCT UK national-phase translation?

No. Although direct UK application documents may be in English or Welsh, the necessary translation for PCT entry into the UK national phase is into English.

Does the PCT 31-month deadline run from the international filing date?

It normally runs from the earliest priority date. If there is no priority claim, it runs from the international filing date. Have the date verified from the PCT record rather than calculating it from the WO publication date.

Must I translate a foreign priority application when I file in the UK?

Not routinely. UKIPO may direct the applicant to file a translation or an appropriate complete-translation declaration if the priority disclosure becomes relevant during substantive examination.

What happens if an Article 19 or Article 34 amendment is not translated?

Where the application translation and national fee were supplied but a necessary amendment translation is missing, UKIPO may issue a three-month notice. If the requirement remains unmet, the amendment may be disregarded even though the underlying application continues.

Does UKIPO require a notarised patent translation?

There is no blanket notarisation or apostille requirement for UK patent translations. A professionally certified translation may be useful, but the controlling requirements are completeness, accuracy, the correct version and the applicable deadline.

What evidence can UKIPO request under Rule 115?

If UKIPO has reasonable doubts, it may require evidence establishing accuracy. The appropriate response depends on the notice and may include translator credentials, a signed accuracy statement, independent review, a terminology explanation or corrected pages. Rule 115 does not prescribe one universal certificate.

Do I need to visit a UKIPO office to submit a translation?

Usually not. Patent documents are commonly filed through UKIPO’s online or other authorised electronic routes. Physical filing is not a substitute for careful deadline control, particularly for overseas applicants.

Prepare the Correct Patent Translation Package

Before ordering, ask your UK patent attorney to confirm the source version, target language and controlling deadline. Then send CertOf the foreign-language description or PCT record, all claim sets, drawing text, amendments and any UKIPO notice.

CertOf can prepare a technically consistent, reviewable translation, preserve numbering and formatting, support revisions and provide an accuracy statement where appropriate. CertOf does not act as a UK patent attorney, choose claim scope, provide an address for service or guarantee UKIPO acceptance. To discuss an unusual file before uploading, use the CertOf contact page.