Filing Receipt

When an application is submitted via e-TEAS, the Office immediately issues a confirmation of filing via e-mail that includes the serial number and filing date, and a summary of all the data provided by applicant in the application. This serves as evidence of filing. Applicants who file paper applications receive printed filing receipts that list the application serial number and filing date, the mark, the applicant's name, the goods and/or services, the filing bases, if available; the international class(es), and the address to be used for correspondence.

Source: U.S. Patent and Trademark Office.