How does it work?
The long, difficult road through patent prosecution often ends in abandonment. When an application is abandoned, the prosecution will be closed, thereby ending the hopes and dreams of a prospective inventor as far as gaining a patent on the invention is concerned.

Abandonment happens for a number of reasons; the applicant or patent attorney may formally abandon the application or they may accidentally abandon the application. This occurs when the applicant does not take the appropriate action within the allotted time period.

There are many situations that can lead to abandonment. These include:

• a formally expressed abandonment by the applicant or by the attorney or agent of    record
  
• a failure of the applicant to take the appropriate action at some stage in the prosecution of a nonprovisional application:
• the failure to respond to an Office action
  
• the failure to pay the issue fee
  
• when the normal time period for a provisional application has expired (12 months after its filing date)

There are actually 2 different routes to abandonment. In the first route, the PTO rejects the application because it isn't appropriate; there may be a fatal mistake or the subject matter is just not patentable. The applicant decides he or she can't fix the error and just lets the time to reply expire. Eventually the application will become abandoned. This is termed abandonment for failure to reply within a time period.

Let's use Sarah's case as an example. Sarah has a great idea, but she doesn't quite express it completely in the specification. So, the examiner sends out a first Office action rejecting the application. If Sarah were on the ball, she could have re-written the specification to make it more complete, but she's not. Discouraged by the Office action, Sarah lets the time to reply expire.  In this instance the PTO will simply abandon the application.

The second type of abandonment is known as express abandonment. All that is needed here is for a written declaration of abandonment to be sent in by the applicant. This declaration of abandonment may be signed by the applicant, the patent attorney or agent of record. Once that declaration is sent in the application becomes abandoned.

Exceptions
There are always exceptions, even when dealing with abandoned applications. It can sometimes be possible to revive an abandoned application. However, this is only a possibility if the application was abandoned due to a failure to reply within a time period (if you expressly abandon an application and then change your mind, you cannot revive the application). In addition, the delay in reply must be unintentional and some sort of evidence to prove the unintentional delay must be included. These petitions must also include a reply, a fee and any necessary terminal disclaimers.

A terminal disclaimer disclaims part of the patent term in lieu of the accident that left the application abandoned. For example, if an applicant unintentionally abandoned his or her application and 3 months later filed a petition for unintentional delay, the PTO may subtract the time the application was abandoned (the 3 months) from the patent term.

The PTO always has the last word in determining the type of evidence they will find acceptable on behalf of a petition for unintentional delay. Generally, the PTO will require a listing of the events that transpired to avoid the error resulting in the delay. In addition, a listing of the training and experience of the people who caused the error should also be sent in. Under no circumstances will the PTO allow an applicant who just wanted to hold off on patent related expenses to revive their abandoned patent.