If you have applied for a patent for the same invention anywhere else in the world, India wants to know about it. The disclosure is made on Form 3 — a statement of the foreign applications, and an undertaking to keep the Office informed — and it is one of the few formal requirements that can sink an otherwise perfectly good patent.
The 2024 Rules simplified when it is due. They did not soften what happens when it is missed.
Quick reference
| What it covers | Applications for the same or substantially the same invention filed outside India |
| What it says | Country, number, date, status — and an undertaking to keep the Office updated |
| Due — first | With the application, or within six months of filing |
| Due — second | Within three months of the first examination report |
| Due — on request | Within two months of the Controller asking |
| Extension | Up to three months, on request and payment |
| If it is wrong or missing | A ground of opposition before and after grant, and of revocation |
What has to be disclosed
The duty covers every application filed outside India for the same or substantially the same invention, whether by you or by anyone deriving title from you. For each one: the country, the application number, the filing date, and its current status — pending, published, granted, refused, withdrawn.
It also carries an undertaking to keep the Office informed of the same details for any such application filed later, up to the grant of the Indian patent.
“Substantially the same invention” is read broadly. A foreign application with narrower claims, or a continuation, or a national phase entry from the same PCT application, is within it. When in doubt, disclose.
The three moments it is due
At filing, or within six months. The first Form 3 goes in with the application or within six months of the filing date. For a PCT national phase entry, that means listing the other national phases and the international application itself.
Within three months of the first examination report. This is the 2024 change. Previously the applicant had to file an updated Form 3 every six months, on a rolling basis, for as long as the application was pending — a duty that was hard to track and routinely missed. It has been replaced by a single update: within three months of the date the first examination report issues, you file a Form 3 bringing the foreign details up to date. That is the same window in which you are answering the report, so the two go together.
Within two months of the Controller asking. The Controller may at any point, for recorded reasons, direct you to furnish a fresh Form 3, and you have two months from that direction to comply. This usually happens where the Office has spotted a foreign application you have not mentioned.
Each of these can be extended by up to three months on a request on Form 4, with the fee.
The Office now looks for itself
The 2024 Rules also allow the Controller to use publicly accessible databases to find out about foreign applications and their prosecution. In practice that means the examiner may already have your European search report on the screen when the first examination report is written.
That does not remove the duty. It changes the consequence of ignoring it: an omission the Office can see for itself looks less like oversight and more like concealment.
Prosecution details on request
Separately from the details of the applications themselves, the Controller may require you to furnish details of the prosecution of any foreign application — the search reports, the examination reports, the claims allowed. Courts have held that this means the substance, not a bare list, and that a response which withholds relevant reports is a failure to comply.
The working practice that has grown up is to volunteer the major offices’ reports — typically the US, European and Japanese — rather than wait to be asked.
What non-compliance costs
This is the part that makes Form 3 matter. Failing to disclose foreign applications, or giving false information about them, is a ground of pre-grant opposition, a ground of post-grant opposition, and a ground of revocation — irrespective of whether the invention is new, inventive and useful.
The courts have taken it seriously. Patents have been revoked where the patentee failed to disclose the prosecution history of a corresponding foreign application, and where the response to the Controller’s request was evasive. The invention’s merits did not save them. A lapse can cost a patentee relief short of revocation too: in one well-known case the Delhi High Court vacated an interim injunction the patentee had obtained, because it had not kept the Controller informed.
The position has since softened a little. Revocation on this ground is discretionary, not automatic — the court looks at whether the omission was deliberate and whether it mattered. But the discretion belongs to the court, not the patentee, and the argument is cheap for an opponent to run.
For a competitor, Form 3 is the first thing to check, because it is a formal attack that does not require any technical argument at all.
Getting it right
- Keep a family schedule. One document listing every application worldwide, updated as each moves, is the source for every Form 3.
- File the update with the examination reply. The three-month window after the first examination report is the same one you are using to respond. Treat the updated Form 3 as part of the reply package.
- Disclose broadly. Substantially the same invention is wider than identical claims. Continuations, divisionals, and national phases all go in.
- Answer prosecution requests with the documents, not a summary of them.
- Diarise the Controller’s two-month direction the day it arrives. It is short, and it is extendable only on request.
Frequently asked questions
What is Form 3 in Indian patent practice? The statement and undertaking in which an applicant discloses applications filed outside India for the same or substantially the same invention — country, number, date and status — and undertakes to keep the Patent Office informed of any filed later.
When must Form 3 be filed? With the application or within six months of filing; then, since the 2024 amendment, once more within three months of the first examination report; and at any time within two months of the Controller directing a fresh statement. Each period can be extended by up to three months on request.
Do I still have to file Form 3 every six months? No. The rolling six-monthly update was abolished in March 2024. It has been replaced by a single update within three months of the first examination report, plus any fresh statement the Controller specifically asks for.
What happens if I do not disclose a foreign application? Non-disclosure, or false disclosure, is a ground of pre-grant opposition, post-grant opposition and revocation, independent of the merits of the invention. Patents have been revoked on this ground, and a lapse has also cost a patentee an interim injunction. Revocation is treated as discretionary rather than automatic, but the discretion is the court’s.
Does the Patent Office check foreign applications itself? Since 2024 the Controller may consult publicly accessible databases to find foreign applications and their prosecution. That does not remove the applicant’s duty to disclose; it means an omission is more likely to be noticed.
What counts as “substantially the same invention”? It is read broadly — continuations, divisionals, applications with narrower or reworded claims, and national phase entries from the same PCT application all fall within it. If a foreign application shares the inventive concept, disclose it.
Useful official resources
- IP India — patents — Form 3, Form 4 and fees
See our related notes on every stage from filing to grant, the foreign filing licence and entering the PCT national phase in India.
An examination report has issued and the Form 3 update is due alongside the reply? Talk to us.