Major: Postmark Date Change Rule

Recent changes to USPS regulations make clear that mail deposited at a local post office or placed in a collection box may not receive an official postmark until it reaches a regional processing center—often a day or more after the item is dropped off. If you choose, or are required, to file any return(s) on paper and/or remit payment by paper check, you are solely responsible for securing a timely, verifiable postmark to establish compliance with filing and payment deadlines. Acceptable proof of timely mailing includes: (i) a manual postmark applied at a local post office counter; (ii) registered mail; or (iii) certified mail.

Look at the new Mailbox Rule