Section 45 of the Patents Act, 1970
Date of patent
Section 45 fixes the date of a patent as the filing date of its application, not the date on which the patent was granted.
Official legal text
The verbatim statutory text of this provision is reproduced from the official source and checked by our legal reviewer before it is published here. Until that check is complete for this page, read the exact wording directly from the official source linked below — it is the only version that governs.
This is a simplified explanation. Where it differs from the official text of the provision, or from an applicable Gazette notification, the official text and the notification prevail.
What this section says, in plain language
There are two dates on every Indian patent that people confuse. The date of grant is the day the Controller granted it. The date of the patent is something else, and section 45 fixes it. Every patent is dated as of the date on which the application for the patent was filed, and that date is entered in the register.
This has a hard commercial consequence. The term of twenty years under section 53 runs from the date of filing of the application. Renewal fees are calculated from the date of the patent. So a prosecution that takes six years does not push the expiry date six years later; it simply means the patentee has fourteen years of enforceable life instead of twenty. Slow prosecution costs term, and expedited examination exists partly for that reason.
Several situations have their own answer. A divisional application filed under section 16 takes the date of the original application from which it was divided. A national phase application under the Patent Cooperation Treaty takes the international filing date. Where an application has been post-dated under section 17, the patent is dated from the new date. Priority claimed from an earlier application under section 11 fixes the date of the claims for the purposes of novelty and inventive step, but the date of the patent, and therefore the term, is worked out from the Indian filing.
The proviso surprises many patentees. No suit or other proceeding may be commenced or prosecuted in respect of an infringement committed before the date of publication of the application. So although the patent is dated from filing, the enforcement window does not open until publication. The position on acts done between publication and grant is dealt with by section 11A, which gives the applicant rights from publication that become enforceable only after grant, and with the conditions that section sets out.
The practical instruction is simple. Diary renewals from the date of the patent, not from the date of grant. This is one of the most common causes of a patent lapsing in India, particularly where a patent is granted late and several years of renewal fees fall due together within a short window under the Rules.
Why this section matters
Every patentee and licensee, and anyone valuing a patent, calculating its remaining life or scheduling renewal payments.
It matters from grant onwards, and especially when renewals are diarised and when the remaining term is calculated for a transaction.
It creates the fixed reference date for the patent: the filing date of the application, which drives the term and the renewal schedule.
Renewals are calculated from the wrong date, fees are paid late or missed, the patent lapses, and the remaining term is overstated in valuations and licence negotiations.
How it works in practice
Six years of prosecution, fourteen years of patent
Ridham Textiles Pvt Ltd files its complete specification for the yarn tension sensor on 14 February 2019. Examination is slow, two hearings are needed and the patent is finally granted on 3 August 2025. The company's operations manager assumes the patent runs for twenty years from grant and tells the board it expires in 2045. Its patent agent corrects the position. Under section 45 the patent is dated 14 February 2019, and under section 53 the twenty-year term runs from that filing date, so it expires in February 2039. Because grant came more than six years after filing, the renewal fees for the intervening years fall due together within the short window allowed by the Rules, and missing that window would let the patent lapse almost immediately after grant. The agent files the accumulated renewals in time and diarises every subsequent renewal from the February anniversary rather than the August grant date.
Simplified illustration only. Actual legal outcomes depend on the facts.
Key points to remember
- A patent is dated as of the date the application was filed, not the date it was granted.
- The twenty-year term under section 53 runs from that filing date, so slow prosecution shortens enforceable life.
- Renewal fees are calculated from the date of the patent and are payable from the third year at the rates in the First Schedule.
- A divisional application takes the date of the parent, and a national phase application takes the international filing date.
- No proceedings can be brought for infringement committed before the date of publication of the application.
- The date of the patent is entered in the register and should be the basis for every renewal diary entry.
Common mistakes and misunderstandings
- Calculating the twenty-year term from the date of grant. The term runs from the filing date, and the difference can be years.
- Diarising renewals from the grant date. Where grant is late, accumulated renewal fees fall due within a short window and the patent can lapse immediately.
- Assuming the patent can be enforced for the whole period since filing. No proceedings lie for infringement committed before the application was published.
Connected provisions
This page explains a section of the Patents Act, 1970. The working detail that goes with it lives in the Patents Rules, 2003. The connected rules appear in their own block so that the statutory duty and the procedural steps stay clearly distinguishable when you cite either one.
Forms, deadlines and fees
- The twenty-year term runs from the date of filing of the application, whatever the date of grant.
- Renewal fees are counted from the date of the patent and become payable from the third year onwards.
- Where a patent is granted late, accumulated renewal fees must be paid within the period allowed by Rule 80; check the current Rule.
Open the deadline calculator — and have every date confirmed against the current Rules before you rely on it.
We do not publish fee amounts. The First Schedule sets them, and they differ by category of applicant, such as a natural person, a startup, a small entity or another applicant, and by the mode of filing. Check the Schedule currently in force before you calculate anything. How Indian patent fees work.
Related judgments
Case law is added slowly and deliberately. A summary is drafted, checked against the reported judgment and then reviewed before publication, because a wrong case note can mislead a reader badly. No summary for this provision has reached publication yet. How case notes are prepared.
Questions people ask about Section 45
Is the twenty-year term counted from filing or from grant?
From filing. Section 45 dates the patent as of the date the application was filed, and section 53 runs the twenty-year term from the date of filing of the application. The date of grant does not extend the term. This is why a long prosecution is costly in commercial terms, and why applicants with time-sensitive technology consider expedited examination. When valuing a patent or negotiating a licence, always work from the filing date to calculate the remaining life.
What is the date of the patent for a PCT national phase application?
For an application entering the Indian national phase under the Patent Cooperation Treaty, the international filing date is treated as the date of the application in India, so the patent takes that date and the term runs from it. That is important for national phase filings, because entry into the Indian phase happens well after the international filing date but does not create a fresh starting point for the term. The remaining life should therefore always be calculated from the international filing date.
Can I sue for infringement that happened before my patent was granted?
Not for acts committed before the application was published. Section 45 expressly bars proceedings in respect of infringement committed before the date of publication of the application. For the period between publication and grant, section 11A gives the applicant rights and privileges as though the patent had been granted on the date of publication, but proceedings cannot be started until the patent is actually granted, and that section sets out the conditions. The remedy is exercised after grant, looking back at that period.
What date do I use for renewal fees?
The date of the patent, which is the filing date, not the date of grant. Renewal fees run from that anniversary and are payable from the third year onwards at the rates in the First Schedule. Where a patent is granted several years after filing, the renewal fees for the intervening years fall due together within the short period allowed by the Rules, and Rule 80 should be checked in its current form. Missing that window is one of the most common ways an Indian patent lapses soon after grant.
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