This brief note is not legal advice and is for educational purposes only.
So, you’re checking your issued patent and low and behold there are errors in the specification and/or more critically in the claims. If the USPTO is at fault, like not entering the language from a response properly, etc. you do not have to pay to get it fixed (but you do need to document that it was USPTO error). On the other hand, if you messed up and it’s minor typographical errors, you may be able to get it corrected by paying a fee. In either case or both cases you will be filing a REQUEST FOR CERTIFICATE OF CORRECTION under 37 CFR 1.322 (USPTO’s mistake) and/or 37 CFR 1.323 (Applicant’s mistake). You will need to file a Certificate of Correction form PTO/SB/44 detailing the corrections you are requesting.
The partial screen shot below shows an example of the format for the changes as issued on a Certificate Of Correction when issued by the USPTO. Please note that since the patent has issued, it will NOT be altered but rather the Certificate Of Correction will be in the patent file and noted. (Some inventors get upset because they believe the patent will be issued with the corrections made.)
A Certificate Of Correction can be issued to correct typographical errors in the specification and errors in the claims if they are minor and the Applicant’s fault (with a fee) or any errors that were made by the USPTO (free of charge).