Did you miss a deadline with the Patent Office or pay the wrong fee? Doing these things, and some others, can cause your application to become abandoned. An abandoned application isn’t necessarily dead. You have a couple of options.
First, if you suspect that it was the Patent Office’s fault that your application was abandoned, you can ask for the holding of abandonment to be withdrawn.
If, however, the application was abandoned without fault by the Patent Office, you’ll have to admit it by filing a petition that says the delay in filing the proper action was either unintentional or unavoidable. A petition claiming unintentional delay must be filed within a certain amount of time and the petition must be accompanied by a fee. A petition claiming unavoidable delay doesn’t have such a deadline, but also must be filed along with a fee.