Application and prosecution.

A patent is requested by filing a written application at the relevant patent office. The person or company filing the application is referred to as "the applicant". The applicant may be the inventor or its assignee. The application contains a description of how to make and use the invention that must provide sufficient detail for a person skilled in the art (for example, the relevant area of technology) to make and use the invention. In some countries there are requirements for providing specific information such as the usefulness of the invention, the best mode of performing the invention known to the inventor, or the technical problem or problems solved by the invention. Drawings illustrating the invention may also be provided.

The application also includes one or more claims that define what a patent covers or the "scope of protection".

After filing, an application is often referred to as "patent pending". While this term does not confer legal protection, and a patent cannot be enforced until granted, it serves to provide warning to potential infringers that if the patent is issued, they may be liable for damages.

Once filed, a patent application is "prosecuted". A patent examiner reviews the patent application to determine if it meets the patentability requirements of that country. If the application does not comply, objections are communicated to the applicant or their patent agent or attorney through an Office action, to which the applicant may respond. The number of Office actions and responses that may occur vary from country to country, but eventually a final rejection is sent by the patent office, or the patent application is granted, which after the payment of additional fees, leads to an issued, enforceable patent. In some jurisdictions, there are opportunities for third parties to bring an opposition proceeding between grant and issuance, or post-issuance.

Once granted the patent is subject in most countries to renewal fees to keep the patent in force. These fees are generally payable on a yearly basis. Some countries or regional patent offices (e.g. the European Patent Office) also require annual renewal fees to be paid for a patent application before it is granted.