Nov 21, 2018 · The tracking number is the unique identifier for your package. Most USPS tracking numbers are 22 numbers long, arranged in groups of four digits, such as 9400 1234 5678 9999 8765 00. However, there are many formats, among them tracking numbers that start with the letters "EC" or "CP," which indicate that the package is being mailed overseas.
Apr 14, 2014 · Pursuant to 26 U.S. Code Section 7502, if the return was post marked before the deadline, in this case prior to April 15th, but delivered by the USPS after the filing deadline of April 15th, then the postmarked stamped on the envelope is deemed the date of delivery or the date of payment.
Track a Package. Informed Delivery. Find USPS Locations. Buy Stamps. Schedule a Pickup. Calculate a Price. Look Up a ZIP Code ™ Hold Mail. Change My Address. Rent/Renew a PO Box. Free Boxes. Click-N-Ship