Revival based on unintentional delay

Deciding Office: Office of Petitions

Selected types of these petitions can also be filed as ePetitions [PDF].

The criteria for a petition requesting revival based on unintentional delay are set forth in 37 CFR 1.137(b), MPEP § 711.03(c)

In general, these are the steps for filing a petition requesting revival based on unintentional delay:

A petition requesting revival based on unintentional delay under 37 CFR 1.137 (a) must be accompanied by:

(1) the required reply, unless previously filed;

(2) the petition fee as set forth in 37 CFR 1.17(m);

(3) a statement that the entire delay in filing the required reply from the due date for the reply until the filing of a grantable petition pursuant to 37 CFR 1.137 (a) was unintentional; and

(4) any terminal disclaimer (and fee as set forth in 37 CFR 1.20(d)) required by 37 CFR 1.137(d).

Terminal disclaimers are required with utility/plant application filed before June 8, 1995, and with any design application regardless of its filing date.

Where there is a question as to whether either the abandonment or the delay in filing a petition under 37 CFR 1.137 was unintentional, the Director may require additional information.

Additional information:

The USPTO requires additional information concerning whether a delay in seeking the revival of an abandoned application was unintentional where the petition to revive was filed more than two years after the date the application became abandoned. See Clarification of the Practice for Requiring Additional Information in Petitions Filed in Patent Applications and Patents Based on Unintentional Delay, 85 FR 12222 (March 2, 2020). 

MPEP § 711.03(c)(II)(C)-(F) contains additional guidance on the information required to establish that the entire delay was unintentional. 


For the proper petition fee required for a petition requesting revival based on unintentional delay, please consult the current USPTO Fee Schedule for code 1453/2453/3453 (Large Entity/Small Entity/Micro Entity) under the Patent Petition Fees.

How to file:

Selected types of these petitions can be filed as ePetitions [PDF].

If not being filed as an ePetition, this petition may be filed using any of these delivery methods.

For the relevant patent laws and rules applicable to revival based on unintentional delay, please see:

  • 37 CFR 1.17, Patent application and reexamination processing fees;
  • 37 CFR 1.137, Revival of abandoned application, or terminated or limited reexamination prosecution;
  • 37 CFR 1.321, Statutory disclaimers, including terminal disclaimers;
  • MPEP § 711.03, Petitions relating to abandonment; and
  • MPEP § 1490, Disclaimers.


The following forms are available:  Petition Form PTO/SB/64, and Terminal Disclaimer Form PTO/AIA/63.

For further assistance, please contact the Petitions Help Desk between 8:30 AM - 5 PM (ET).


The Federal Register is the authoritative source and should be consulted if a need arises to verify the authenticity of the language for any CFR citation.  Because fee schedule changes may not be reflected in the most recent version of the MPEP, please consult the USPTO Fee Schedule to determine current fee amounts.