Priority Date explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
In an Indian patent each claim has its own priority date, and that date decides what prior art can be set against it. Paragraph 05.04 of the Manual, with 05.04.01 to 05.04.04, explains how the Office fixes the date in the common situations. The statutory rule is in section 11; this article covers how the Office applies it.
The priority date of a claim is normally the filing date of the application, if the claim is fairly based on the matter disclosed. After a provisional it is the provisional's date, but only for matter disclosed there; a claim based partly on one filing and partly on another takes the later date. A divisional takes the date of the first application and a convention application takes the date of the basic foreign filing. The Manual is the Patent Office's guidance and does not have the force of law; the Patents Act, 1970 and the Patents Rules, 2003 as now in force prevail.
Check the current Manual on ipindia.gov.in. See section 11: priority dates of claims for the section. If you are planning a filing sequence, a provisional patent filing strategy should be set against these rules from the start.
The general rule (05.04)
The Manual says each claim of a complete specification has a priority date. When the complete specification is filed with the application, the filing date is the priority date of each claim fairly based on the matter disclosed in it. "Fairly based" is the test the Office applies, claim by claim.
The situations in 05.04.01
| Situation | Priority date the Manual gives |
|---|---|
| Complete specification filed pursuant to a provisional | Filing date of the provisional |
| Complete specification based on two or more cognate provisionals | For claims from each provisional, the date of that provisional |
| Complete specification converted into a provisional, and a fresh complete specification filed | The date of disclosure of the specification in which the claimed matter was first disclosed |
| Provisional cancelled and the application post-dated, on request before grant | The date of the complete specification (the provisional is post-dated) |
| Claim fairly based partly on one earlier application and partly on another | The date of the later filed specification |
| Complete specification based on a previous Indian application filed within twelve months | The date of the previous application where the matter was first disclosed, if the claim is fairly based on it |
The last two rows are where applicants are most often surprised. If a claim combines a feature from provisional A with a feature from provisional B, it does not take A's date; it takes B's. Drafting claims so that each depends on a single earlier disclosure keeps the earlier date for as many claims as possible. Our article on the provisional specification explains why the provisional must carry enough detail for this.
Protection against later events
The Manual adds that a claim is not invalidated merely because the invention was published or used on or after the priority date of the claim, or because another patent claiming the same invention was granted with the same or a later priority date. In other words, the date works as a shield against what happens after it.
Divisional, convention and the effect of the date
- Divisional application (05.04.02). The priority date of the claims is the date of filing of the first-mentioned application. See our article on divisional applications.
- Convention application (05.04.03). The priority date is the date of filing of the basic application in the convention country. The mechanics are in our article on convention applications.
- Effect (05.04.04). The novelty of a claim depends on its priority date. Nothing published on or after the priority date of a claim can be cited to destroy the novelty of that invention.
For a PCT national phase application, the priority date follows the international application and is dealt with in Chapter 7 of the Manual. A grace period application under rule 29A is a separate matter, covered in the rule 29A post and not part of this Manual chapter, which predates it.
How the examiner uses the date
In examination the Office searches for prior art published before the priority date of each claim. Where a claim relies on two filings, the examiner will treat the later filing date as the date for that claim, and anything published between the two dates can then be cited against it. The usual objection is therefore not that the date is wrong but that a document published between the dates anticipates the claim.
The applicant's reply has three options: show that the claim is fairly based on the earlier filing alone, so that the earlier date applies; amend the claim so that it is; or argue on novelty and inventive step against the cited document on its merits.
| Examiner's question | What the applicant shows |
|---|---|
| Is each claim fairly based on the matter disclosed in the earlier filing? | A passage-by-passage map of each claim to the provisional or earlier application |
| Does a claim combine matter from two filings? | An acceptance that the later date applies, or an amendment to split the claim |
| Is the cited document published between the dates? | Argument on the merits, or evidence on the priority date |
| Was the earlier Indian application filed within twelve months? | The filing dates, shown on the record |
Worked example
Samira Qureshi Pvt Ltd files provisional A in March for a motor controller and provisional B in August for a sensor housing, then files one complete specification within twelve months of the first. Claims 1 to 5 relate only to the controller disclosed in A, and take March as their priority date. Claim 6 combines the controller with the housing disclosed in B and takes August. A paper published in June, between the two dates, is cited against claim 6 but cannot be cited against claims 1 to 5.
Need help with priority strategy?
Choosing what to put in each provisional decides which claims keep the earlier date. Our provisional patent filing team can map your claims to your filings before the complete specification is prepared.
Key takeaways
- Each claim has its own priority date, and the test is whether it is fairly based on the earlier filing.
- A claim based partly on one filing and partly on another takes the later date.
- A divisional takes the first application's date; a convention application takes the basic application's date.
- Nothing published on or after a claim's priority date can be cited to destroy its novelty.
- The Act and Rules as now in force prevail over the Manual.
Read next
- Chapter 5: the specification and the provisional specification
- Chapter 6: divisional applications and patents of addition
- Chapter 7: convention applications
- Section 11: priority dates of claims
Disclaimer: Based on the manuals and guidelines published by the Office of the Controller General of Patents, Designs and Trade Marks that are named in the article, as consulted on 4 October 2026. They are guidance and do not have the force of law; the Patents Act, 1970 and the Patents Rules, 2003 as amended (including the 2024 amendment rules) prevail, and the current versions on ipindia.gov.in should be checked. This article is general information, not legal advice; check the official text before acting.