Priority Mail
A USPS service offering 1-3 day delivery for packages and thick envelopes, with free packaging supplies, tracking, and up to $100 of included insurance.
Priority Mail is the USPS's flagship expedited delivery service for packages weighing up to 70 pounds. Delivery time is typically 1-3 business days depending on origin and destination, though it is not guaranteed (Priority Mail Express provides a money-back guarantee). The service includes USPS tracking, $100 of insurance at no extra cost, and free Flat Rate and Regional Rate packaging materials.
Priority Mail pricing follows two models: weight-based (charged by weight and distance using postal zones, which are derived from the origin and destination 3-digit ZIP code prefixes) and Flat Rate (a fixed price regardless of weight for USPS-supplied boxes and envelopes).
Commercial mailers access lower Priority Mail rates through online postage platforms or USPS Commercial Plus pricing. Postal zones, which determine weight-based pricing, are calculated from the origin and destination ZIP code's SCF relationships.