In my previous post What do Contingent Fee Patent Lawyers Look for When Considering Patent Title and Term?, due diligence should include consideration of issues relating to patent term. This analysis considers term extension and terminal disclaimers, maintenance fees, and limitations on damages. Is there a good way to discern and organize this information?

One way independent inventors and patent owners can track the patent terms of each of the patents in a portfolio is with a spreadsheet containing columns for at least the following information:

Application Number (APN)
Patent Number (PN)
Earliest Priority Date (Earliest Priority).
Filing Date for the Application.
Issue Date for any Patent Issuing from the Application.
Jurisdiction (e.g., US)
Current Status (e.g., Expired Provisional, Pending, Issued, Abandoned Application)
Terminal Disclaimer Information.
Term Extension Information (number of days; note if eliminated due to a terminal disclaimer).
Calculated Estimated Expiration Date.
- Excel Equation: =[Earliest Priority Date Cell]+(20*365.25)+[Term Extension Cell]
Calculated Estimated End of the Period of Enforceability under 35 USC 286.
- Excel Equation: =[Estimated Expiration Date Cell]+(6*365.25)
Calculated 3.5-, 7.5- and 11.5-year maintenance fee deadlines. These can be color-coded based on the payment status of the maintenance fee.
- 3.5-year Excel Equation: =[Issue Date Cell]+3.5*365.25
- 7.5-year Excel Equation: =[Issue Date Cell]+7.5*365.25
- 11.5-year Excel Equations: =[Issue Date Cell]+11.5*365.25

All of the above information, except the calculated information, can be obtained from the face of each issued patent, the file histories of each application via the USPTO’s PAIR website, and the USPTO’s Maintenance Fee Database.

An example portion of a Term and Maintenance Fee Tracking spreadsheet (partially redacted).

At some point near the end of a licensing program, patents may issue with limited term near the end of the period of enforceability. For these patents, some of the maintenance fees may be due after the patent expires (due to terminal disclaimers). To the extent a patent expires before a maintenance fee date, there is no need to pay the maintenance fee. This type of spreadsheet can be used to note which maintenance fees will never become due in this regard.

In practice, we have a maintenance fee service manage the payment of the maintenance fees; however, this tool is useful to make sure we docket the dates and double check that the service pays the maintenance fees on time.