What happens if the date of receipt stamp is illegible or missing?

If the date of receipt stamp is illegible or missing, the USPTO will make every effort to determine the correct date of receipt. This may involve examining other evidence, such as postmarks, electronic filing receipts, or other documentation. If the correct date cannot be determined, the USPTO may use the date it was discovered that the document was received as the date of receipt. Applicants should always ensure that their submissions are properly dated and stamped to avoid potential issues with filing dates.