• If you want to get something on file before going to a trade show or offering your product for sale, but do not want to take the time or spend the money for a full-blown patent application before finding out whether the product will sell.
  
  
• At the last minute, someone is going to give a speech disclosing his invention, which would destroy his foreign patent rights. We can file the text of the speech as a provisional patent application, which preserves the right to apply for foreign patents.

Filing a provisional application is not a wasted effort, because the information from the provisional application can be used later in preparing the regular patent application. The only cost that cannot be applied toward the regular patent application is the PTO filing fee, which is low -- $75 for small entities and $150 for large entities.

CAUTIONARY NOTES:

• A regular application must be filed within one year of filing the provisional in order to take advantage of the filing date of the provisional application. If no regular application is filed within the year, the provisional application simply expires.
  
  
• Any foreign filing must be done within one year of filing the provisional if the provisional is to be considered the original U.S. application.
  
  
• A provisional patent application is only useful to the extent that it discloses the invention you later want to claim.