USPS Mailing Deadlines
Dec. 15 – Standard Service
Ground service for less-than-urgent deliveries and over-sized packages.
Dec. 19 – First Class Mail®
Service for standard-sized, single-piece envelopes and small packages weighing up to 13 ounces with delivery in 3 business days or less.
Dec. 21 – Priority Mail®
Domestic service in 1, 2, or 3 business days based on where your package starts and where it’s being sent, variety of Flat Rate options.
Dec. 23 – Priority Mail Express®
Fastest domestic service, guaranteed overnight scheduled delivery to most locations. Some restrictions and exceptions apply.
Also note: Priority Mail Express postage refund eligibility is adjusted for shipments mailed Dec. 22 through Dec. 25.