PCT National Phase in United Kingdom: 6 Smart Steps

If you filed an international patent application under the Patent Cooperation Treaty and Britain is a market you care about, the clock that matters is the one running to the PCT national phase in United Kingdom. Miss it and the UK simply falls out of your patent family. Enter it correctly and you keep the option of a UK patent enforceable in one of Europe’s busiest patent courts. This 2026 guide covers the 31-month deadline, the two ways into the UK, the current UKIPO fees, and the late-entry lifeline that saves more applications than most inventors realise.

What the PCT National Phase in United Kingdom Means

A PCT application does not grant a worldwide patent — there is no such thing. It buys you time and a single filing date across more than 150 countries, after which you must enter the national or regional phase in each place you actually want protection. Entering the PCT national phase in United Kingdom is how you turn that international filing into a pending UK patent right.

There are two routes into the UK, and the choice has real consequences. You can enter the national phase directly at the UK Intellectual Property Office (UKIPO), or you can enter the European regional phase at the EPO and designate the UK — a granted European patent then takes effect in the UK automatically. This mirrors the choice we cover in our guide to Euro-PCT regional phase entry, applied to one country.

The 31-Month Deadline You Cannot Miss

The deadline to enter the PCT national phase in the UK is 31 months from the earliest priority date of the international application. That is one month longer than the treaty minimum of 30 months, and it applies whether you take the direct UKIPO route or the European route. It runs from your priority date, not your international filing date, so if you claimed priority from an earlier application the clock started then.

Unlike some offices, the UK does not require you to have entered any regional phase first, and it does not demand a Power of Attorney to enter the national phase. What it does demand is that you hit the date. Diary it from the priority date the moment the PCT is filed, and build in a buffer — a national-phase deadline is one of the least forgiving dates in patent practice.

You can also go early. If you want prosecution to start sooner — to accelerate grant, to support enforcement, or to line up with a product launch — you may enter the national phase before the 31-month date by making an express request for early processing. The trade-off is that you give up the option value of waiting: the extra months exist so you can watch the international search and written opinion, gauge commercial traction, and decide market by market whether the UK still justifies the spend. Enter early only when you have a concrete reason to, not by accident.

Two Routes: UKIPO Direct vs the European Patent

Choosing the route is the strategic heart of UK national-phase entry:

• Direct UKIPO route — you file the national phase at the UKIPO and prosecute a purely British patent. Best when the UK is your main or only European market, or when you want to control UK prosecution independently.
• European route — you enter the EPO regional phase, designate the UK, and once the European patent grants it takes effect in the UK with no separate validation step and, because the EPO grants in English, no translation. Best when you want the UK alongside several other European countries from one prosecution.

One post-Brexit point is easy to get wrong: the United Kingdom left the Unified Patent Court system, so a European patent covering the UK is enforced as a national UK right in the UK courts, never in the UPC. A validated European patent (UK) and a directly-filed UK patent end up in the same enforcement forums. For context on the national alternative, see our guide to validating a European patent in the United Kingdom.

2026 UKIPO Fees and What Triggers Them

The UKIPO increased its fees on 1 April 2026 — the first rise since 2018 — so budget on the current figures rather than older guides. Entering the national phase itself is cheap; the substantive costs come from search and examination:

• National-phase entry fee (Patents Form NP1): GBP 40.
• Search fee for a national-phase application filed online: GBP 160.
• Substantive examination fee filed online: GBP 130.
• Excess-claims and excess-page fees can apply, so trim the claim set before entry where you sensibly can.

Because a PCT application has already been searched internationally, the UK search fee is lower than for a first UK filing. Confirm the current schedule on the UKIPO’s own fee sheet before you pay, as figures change.

The 6 Steps to Enter the UK National Phase

1. Diary the 31-month deadline from the earliest priority date the moment the PCT is filed.
2. Decide the route — direct UKIPO or the European regional phase — based on how many European countries you need.
3. File Patents Form NP1 at the UKIPO and pay the GBP 40 national-phase entry fee before the 31-month date.
4. File an English translation of the international application if it was not published in English.
5. Request search (generally within two months of entering the national phase, or by 12 months from priority) and pay the search fee.
6. Request substantive examination and pay its fee by 33 months from the priority date, then prosecute to grant.

Most PCT applications are published in English, so for English-language applicants the translation step usually falls away — but confirm the publication language before you rely on that.

Missed the Date? The Late-Entry Lifeline

A missed national-phase deadline is not always fatal in the UK, which is more forgiving than many offices. You can enter the national phase up to two months late as of right on payment of a surcharge, provided the failure to meet the 31-month date was unintentional — effectively extending the practical deadline to 33 months.

Beyond that window, reinstatement is discretionary: you must satisfy the UKIPO that there was always an underlying intention to enter the UK national phase, and the office weighs the evidence before allowing it. Discretion is never guaranteed, so treat the two-month extension as an emergency brake, not a plan. If a deadline is slipping, get advice immediately rather than after it passes.

Enter the UK National Phase Without Losing the Date

PerspireIP manages PCT national-phase entry into the United Kingdom end to end — route strategy, UKIPO filing, translations, search and examination requests, and the docketing that keeps the 31-month date from slipping. We support inventors and counsel across the UK, from London to Manchester and beyond, and coordinate the UK with your wider European filings. Talk to our patent team or explore our United Kingdom services hub to plan your entry.

Frequently Asked Questions