usps overnight flat rate

usps overnight flat rate USPS offers overnight delivery through its Priority Mail Express service, which includes a flat rate pricing option. With USPS Overnight Flat Rate, customers can ship packages of various sizes for a fixed price, regardless of weight (up to 70 lbs). This service is ideal for fast, guaranteed delivery by 3:00 PM the next day. Flat rate envelopes and boxes are available, offering a convenient and predictable cost for urgent shipments within the United States.