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Patent criticality
Nobody decided what the priority date was for
When exactly should the first application be filed?
Priority is not a property of your application. It attaches, claim by claim, to whatever was fairly disclosed in the filing you are relying on. Treating it as a single date for the whole case is how applicants discover, years later, that half their claims have a later priority than they assumed.
What the strategy has to decide
When there is enough technical substance to disclose the invention meaningfully - too early and the priority document supports nothing; too late and someone else, or your own disclosure, gets in first.
What the twelve months will be used for: further data, further embodiments, a decision on markets, a PCT filing.
And whether there will be more than one priority filing. A second provisional for later developments is often better than cramming everything into one late filing - but each one starts its own twelve-month clock and the interaction has to be managed.
The failure mode
A thin provisional in March, a rich complete specification the following March, and a competitor publication in September. The claims supported by the thin provisional are safe. Everything added later is not - and it is usually the added material that describes the product you are actually selling.
Sections 9, 11 and 135 of the Patents Act 1970; Paris Convention priority.
Write down, at the time of the first filing, exactly which subject matter you believe it supports. That list is what your priority claim is worth.
Filing a placeholder provisional and treating the date as covering everything that follows.
Complete specifications that are much longer than the provisional they claim priority from.
For your most important pending case, mark each independent claim with the filing that first disclosed it. That is your real priority position.
Sources & further reading
- The Patents Act, 1970 (consolidated to 1 August 2024) — Official IP India text
Related
Priority date
The earliest date to which a claim is entitled - usually the date of your first filing for that subject matter. Prior art is judged against it.
Provisional specification
A first filing that describes the invention but need not contain claims. It secures a priority date, and a complete specification must follow within twelve months or…
The provisional that covered nothing
A provisional specification buys a date for the subject matter it actually describes. A two-page document that states the idea without explaining how it works buys a…
The twelve months that decide your international position
Twelve months from your first filing, you must either file in each country you care about, or file a PCT application that preserves the option. There is no third cho…
Thinking about filing?
Before anything is drafted, the useful work is establishing what is already public, what is genuinely yours, and what you can honestly claim.
Educational guidance, not legal advice. This material is published by Ragulika IP for general education and information. It is not legal advice, it does not create a professional-client relationship, and it is not a substitute for advice on your own facts. Patentability, infringement, prosecution strategy and every other IP outcome turn on the specific facts and on the law and Patent Office practice as they stand at the time you act. Please take professional advice before making a decision, and read the underlying provision or judgment before relying on any point stated here.
Last reviewed by Ragulika IP on 2026-08-23. Indian patent law and Patent Office practice change; check the position before you rely on it.