Filed application for patent filed in the United States may claim the benefit of, or priority to, a prior application filed in the United States. What is a patent priority date?Priority date refers to the earliest filing date in a family of patent applications. An applicant who claims the priority of one or more earlier national, regional or international applications for the same invention must indicate on the Request Whoever was first to sell goods or services under a particular mark will typically be deemed the rightful trademark owner. This is known as trademark priority. The priority date determines whether another patent filing or publicly available document qualifies as prior art against one's patent application. A priority claim is made to an earlierfiled patent application. For example, an Applicant can claim priority in a later-filed patent application. A priority claim is filed when a trademark owner wants to use its first filing date from an application filed in another country within the past six months.