An issued US patent only provides protection within the United States. You must file in each country that has a patent system if you wish to obtain patent coverage elsewhere. While there are well over 150 countries that have a patent system, most people limit the foreign filing of patent applications to the top few countries that represent the largest markets for their invention.

You do not have to file in the selected non-US countries at the same time as your first US patent application but you must begin the patent process within 12 months of that first date (earliest of your first well written provisional or regular application) or you will lose all rights to foreign patent protection. You have two choices to begin the process. The first is to file a national application in each of the countries you are interested in. the second is to file a PCT application which in the countries it covers delays by 18 months the requirement to file a nationally based patent application. If you follow the rules properly your foreign patents will benefit from your earliest US filing as if they were filed on the same date.

Foreign filing is an important decision in the patent process if sales are contemplated by your or a licensee outside the US. A through discussion with a patent attorney should be completed before proceeding to file outside the US and to make sure all your foreign rights are preserved.