What is the difference between a patent agent and a patent attorney?

The US Patent Office recognizes and will deal with only two types of individuals for the purpose of prosecuting (meaning conducting legal proceedings or making legal) a patent application:

A patent agent is not a lawyer . A patent agent can only represent you before the United States Patent and Trademark Office (PTO), which is an administrative agency of the United States government. What if you appeal your patent application to the Board of Patent Appeals and Interferences (part of the PTO) and lose, and want to appeal to district court or the Court of Appeals for the Federal Circuit, as is your right? A patent agent cannot do that. What if you want some help with a licensing agreement or some advice about what constitutes infringement of your patent? A patent agent cannot help you with those issues- it would be against the law for a patent agent to give you such advice. A patent agent cannot help you with infringement issues or licensing issues, or with corollary issues such as trademarks, copyrights, or trade secrets. This goes beyond what they are licensed to do- practice before the Patent Office. You do not need to have any knowledge of the broader legal issues ...  more

A patent agent must pass the patent registration examination the US Patent Office offers at hundreds of locations around the country. A patent attorney must also pass this US Patent and Trademark Office registration examination, but must, in addition, have studied law. Patent attorneys are more qualified to litigate before the US patent office in patent prosecution than patent agents.  more

Nhung: The patent agent can represent an inventor only before the PTO. The patent agent is not supposed to give legal advice outside the scope of representation before the PTO. For example, a patent agent should not render advice on infringement of a patent. Brian: Do I need to go back to school to become a Patent Agent? Nhung: You do not need to go back to school. However, you do need to study, either on your own, or by taking one of the "patent bar review" courses that are offered by different organizations. Then, you would have to take and pass the "patent bar" exam given by the PTO. Brian: Why would some people choose to be Patent Agents, others choose to be Patent Attorneys? Nhung: It is really not simply a matter of choice, but a question of making the best of your circumstances, at the point where you stand in your career in chemistry. In the "old days" many chemists went to law school part-time at night, while working full-time as a patent professional (in a law firm, in the ...  more

In the UK there's no requirement to use a patent attorney to represent you before the UK Patent Office, but it's a very good idea to get professional advice in something as complex as patent law. If you file a patent application which then becomes published, then your invention will become known and you'll have lost your opportunity to file a subsequent patent application if the first one didn't do what you thought it was going to do.  more