The U.S. Postal Service (USPS) recently updated its guidance on what a postmark date represents. Under the updated Domestic Mail Manual, the postmark date on most mail now reflects the date the item is first processed at a postal facility, not necessarily the date it was placed in a mailbox or collected by a carrier.
This clarification means that the postmark date may be later than the date you mailed your tax return, payment, petition, or claim for refund. Since California law generally considers a document or payment timely if it is postmarked on or before the due date, a later postmark could result in penalties and interest for late filing.
What You Can Do
To avoid late filing penalties and interest:
• File and pay online—Using our Online Services
eliminates concerns about postmark dates.
• Mail early—Send returns and payments several days before the deadline.
• Visit the post office—If mailing close to the due date:
• Request a manual postmark to ensure the date reflects
when USPS accepted your item.
• Obtain a certificate of mailing or use registered or certified mail for proof of mailing.
For more information, visit the Postmarking Myths and Facts webpage or contact our Customer Service Center at 1-800-400-7115 (TTY:711).
