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Patent Legal Status Calculations

The Lens provides Legal Status information for Patents. This information is important to determine whether:

  • examination of a patent application is still pending,
  • the application has been withdrawn or was rejected,
  • patent has been granted and is still valid, or
  • a granted patent has expired, lapsed, or has been revoked.


Filing DateFiling date of the application.
Earliest Actual Filing DateThe actual earliest filing date is the earliest of:The filing date of a non-provisional patent applicationThe filing date of the earliest priority application (i.e. the earliest filed non-provisional)The PCT FilingEarliest in the chain of continuation filings (divisional, continuing,continuation in part)
Priority ApplicationPriority applications can be present when:an applicant seeks protection for the same invention in multiple jurisdictions (including international treaty applications),an applicant seeks protection for a difference invention that builds upon their previous inventions ora combination of the previous two.
Earliest Priority DateThe earliest priority date of the application is the filing date of the earliest patent that disclosed the invention initially. It may include provisional and foreign filing date and is not used as the actual Earliest filing date for the term calculation.
PCT ApplicationA PCT application is filed to obtain patent protection in multiple jurisdictions through the Patent Cooperation Treaty. The application subsequently enters the national/regional phase to each designated jurisdiction.
Divisional ApplicationA patent may protect only a single inventive concept. Further inventive concepts using the same specification may be divided out into new application (divisional) which keep the filing date of the original application (the parent application).
Continuation in PartApplicant modifies some claims, names, or content in a patent application, they will be entitled to file a continuation in part application.
Term ExtensionFor patents regarding pharmaceuticals, food products, medical devices, or procedures, for which a Food and Drug Administration (FDA) approval is required, the term of these patents is usually extended to compensate for the delayed processing time.

The Rejection of a Request for Patent Term Extension event is also considered in the term date calculation and applied to the Expiry Date as received from INPADOC, overriding the term extension in those cases.
Patent Term Adjustment(PTA)If there is a delay caused by USPTO during the prosecution of a US patent application, the applicant can receive an extension to the term if they meet requirements established in 35 USC 154(b)
US Patent Terminal DisclaimerA terminal disclaimer is a process by which a patent’s term is shortened because it duplicates the claims of another patent which expires sooner. Lens only provides a flag if the patents is subjected to terminal disclaimer.

Stages of Prosecution

  1. Filing: The receipt of an application for the grant of an IP right by a national or regional IPO. It includes filing of a provisional, continuing and PCT filing.
  2. Examination: Includes formality and substantive examinations viz. request for examination, request for prior art search, decision to grant, publication, etc but does not include the act of granting and/or registering the IP right itself.
  3. Pre Grant-Challenge: Application review before granting the IP right which includes proceedings such as pre-grant opposition, re-examination, or limitation.
  4. Grant: It includes grant of IP right, publication of document, extension of protection beyond the term etc.
  5. Post Grant Challenge: It includes proceedings such as opposition, re-examination, re-issue, limitation, surrender of the granted and/or registered IP right after IP right was granted.
  6. Termination: IP right is not in force with possibility of revival, terminated by IPO or the court without possibility of revival.

Data Sources and Fields used in the Calculation

EPO worldwide legal event data (INPADOC)1:

  • Application Filing Date
  • Application Revival Date
  • Application Discontinuation Date
  • Natural Term Date (shared through SPC information)
  • Grant Date2
  • IP Right Lapse Date
  • IP Right Reinstated Date
  • Fee Payment History
  • SPC Extended Term Date
  • Designated States
  • Lapsed States

EPO worldwide bibliographic data (DOCDB):

  • Priority Filing

United States Patent and Trademark Office (USPTO):

  • Patent Term Extension
  • Terminal Disclaimers

The Lens:

  • Mapped legal status information
  • Document type identifier mapping

1 INPADOC legal events data is provided by the EPO for information only, and is not a substitute for the official patent register. The EPO loads legal events data as they receive it from respective patent offices. In order to determine the exact expiry date of each patent or SPC, the EPO recommends checking every national register separately. INPADOC provides an overview of events that have taken place at some point in time and is also limited in coverage, for example SPC coverage does not include all national collections. For advice on the legal aspects of event information provided by INPADOC, it is recommended to contact the respective national office or a patent lawyer.
2 For grant date, publication date is used for the granted patents if the grant event is missing. In Lens this is identified by kind code analysis for different jurisdiction.

Rules for Identifying the Earliest Filing

Earliest Application filing can be any one of the following non-provisional applications.

  1. Date of filing of application.
  2. PCT application.
  3. Earliest in the chain of continuation application (continuation, continuation in part, divisional). (e.g., for US5720714A, its earlier PCT application (GB9402410W) filing date will be used). However, for EP0145340B1, the foreign filings US55315783A and US55315883A will be ignored.
  4. If there are multiple continuing applications (divisional, continuing and continuation in part), take the earliest in the chain.
  5. If the PCT filing date follows the other filing, it will be the Earliest filing date in the chain.

Patent Status Calculation

  1. Unknown: If there is not enough information to calculate.
  2. Active: If
    1. Granted and calculated term date is before current date.
    2. It is being renewed.
    3. Latest legal event is not related to withdrawal or lapse.
    4. Regional application is not withdrawn or lapsed in all designated jurisdictions.
  3. Inactive: If it has lapsed but has not revived before the calculated term date or if application Expiry Date is not before Application Revival Date.
  4. Patented: If regional application is alive in at least one state or if it is granted but there is not enough information to mark it as active.
  5. Expired: If Calculated Term Date is Before current date And Unnatural Expiry Date is Before current date.
  6. Pending: IP Right has not been granted yet and application is in either filing, examination, pre-grant stage.
  7. Discontinued: Application was discontinued (rejection, withdrawal, refusal, etc), can be revived.

Term Date Calculation Rules

US Term Rules

  1. If grant date was before 1978/06/05, Add 17 years to the Grant Date.
  2. If, Actual filing date is before 1995/06/08, OR PCT Priority claim date is before 1995/06/08, Term date is earliest of Grant Date plus 17 years and Filing date plus 20 years.
  3. Else, term date is 20 years from the Earliest filing date (earliest of actual filing date and effective priority date)
  4. Domestic priority to one or more U.S. provisional applications is not considered in the calculation of the twenty-year term.
  5. Foreign priority is not considered in determining the patent term.
  6. A patent granted on a continuing application (Continuation, Divisional, or Continuation-in-part) that was filed on or after June 8, 1995, has a term ending 20 years from the filing date of earliest application for which a benefit is claimed, regardless of whether the application for which a benefit is claimed was filed prior to June 8, 1995.
  7. A patent granted on a U.S. national stage application of an international application filed on or after 1995/06/08, has a term ending 20 years from the filing date of the international application.  Similarly, a continuation or a continuation-in-part application claiming the benefit of such an international application has a term of 20 years from the filing date of the parent international application.
  8. A patent granted on a U.S. national stage application of an international application filed before 1995/06/08, has a term that is the greater of the “twenty-year term” or 17 years from the date of grant.

China Term Rules

  1. For Design and Utility Models: Filed on and before 1993/01/01 have 5 years term, and any filed after 1993/01/01 have 10 years term.
  2. For Patents for Inventions:
    1. Filed after 1992/12/31 and were granted 15 years earlier than 2001/12/11 have 20 years term.
    2. Filed before 1993/01/01 have 15 years term.
    3. All others have 20 years term.

Canada Term Rules

  1. For patents filed before 1989/10/01:
    1. If the granted date is after 1984/07/12, the term is 17 years from the grant date or 20 years from the earliest filing date, whichever is earliest.
    2. Otherwise, the term is 17 years from the grant date.
  2. For patents filed on or after 1989/10/01 the term is 20 years from the earliest filing date.

EP Term Rules

  1. The European Patent Convention requires all jurisdictions to give a European patent a term of 20 years from the actual date of filing the application.
  2. The application status will be granted if it is granted in one of the designated jurisdictions.

Other jurisdictions

Term date is 20 years from the earliest filing date for all other jurisdictions.

Know more about the calculation of legal status?
We are always looking to improve our methodology to provide the most accurate data possible. If you know of any regional jurisdictional rules that haven’t been accounted for, we would love to know! Please contact us and help improve the Lens as a public-good for everyone.

Updated on April 8, 2022
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