What happens if the USPTO receives a document without a date of receipt stamp?

If the USPTO receives a document without a date of receipt stamp, the Office will assign the document a date of receipt based on other evidence. This may include:

• The date of receipt indicated on an Express Mail label
• The date of deposit indicated on a certificate of mailing
• The date of transmission indicated on a certificate of transmission
• Other corroborating evidence, such as a postmark on an envelope

In cases where no other evidence is available, the USPTO may assign the date of receipt as the date the document was matched with the file wrapper.