For Immediate Release

January 20, 2026

CA FTB advises taxpayers on USPS postmark updates and filing deadlines

Sacramento – The California Franchise Tax Board (FTB) is alerting taxpayers and tax professionals to recent updates to the United States Postal Service (USPS) transportation procedures that may affect postmark dates on mailed tax returns, payments, and other time-sensitive correspondence.

Effective December 24, 2025, USPS implemented a final rule adding Section 608.11 to the Domestic Mail Manual, clarifying that machine-applied postmarks will generally reflect the date mail is first processed at a regional facility rather than the date an item is dropped off at a local post office or mailbox. Under this new system, the postmark date may occur days after a taxpayer deposited mail with USPS, potentially causing mailed filings to be untimely.

Per the USPS website:

“...[W]e have made adjustments to our transportation operations that will result in some mailpieces not arriving at our originating processing facilities on the same day that they are mailed. This means that the date on the postmarks applied at our processing facilities will not necessarily match the date on which the customer's mailpiece was collected by a letter carrier or dropped off at a retail location.

As before, a customer can ensure that a postmark is applied to his or her mailpiece, and that the date on the postmark matches the date of mailing, by visiting a Postal Service retail location and requesting a manual (local) postmark at the retail counter when tendering their mailpiece. Manual postmarks will be applied free of charge.”

“The recent USPS changes highlight the importance of knowing how your return will be postmarked when submitting it by mail,” said State Controller and FTB Chair Malia M. Cohen. “Under the new system, a mailed return may not be postmarked until it reaches a processing facility, which may be days after drop-off. To help taxpayers avoid late filings and penalties, I strongly encourage e-filing whenever possible, and recommend requesting a manual postmark at a USPS retail counter if filing by mail.”

To avoid a late tax return, tax payment, or other filings, FTB strongly encourages taxpayers to consider e-filing and making e-payments if possible. For those who must file or pay by mail, taxpayers can help ensure they file or pay on time by visiting a USPS retail counter and requesting a manual (local) postmark, obtaining a postage validation imprint, certificate of mailing, using Certified Mail or Registered Mail with documented proof of mailing date.

As a reminder: To avoid penalties, be sure to pay any taxes owed by April 15. Mailers should allow extra time for postmarking and delivery to avoid penalties, interest, or processing issues that could arise if postmarks do not align with statutory deadlines.

File and pay taxes online

For faster service, take advantage of FTB's 24/7 online self-service options.

To e-file your California tax return, visit CalFile, which allows most Californians to e-file their state tax return for free.

FTB offers several payment options. You can pay your taxes with your checking or savings account using Web Pay, by credit card (fees apply), or set up a payment plan if you qualify (fees apply).

For more information on filing options and important tax deadlines, visit ftb.ca.gov or consult your tax professional.