USPS Guide

This guide will teach you what makes USPS different from other carriers.

The goal of this guide is to detail the best and cheapest ways to use United States Postal Service (USPS) shipping. From the best ways to offer returns to the USPS competitive pricing, we will walk you through predefined packages, service levels, labels structures, and pick-up guidelines.

USPS has multiple service levels to support your business' every need. Naturally, the price of shipping packages increases as the delivery time decreases. EasyPost supports all of USPS' functionality, along with the full functionality of 100+ other carriers.

If you haven't shipped your first label with EasyPost, we recommend you check out our Getting Started Guide.

USPS Pricing

There are two USPS pricing tiers: Retail and Commercial.

EasyPost offers the lowest cost tier for all of our customers. Just sign up and get started shipping with Commercial Pricing.

EasyPost also supports Cubic Pricing. Cubic Pricing is based on the volume, in cubic feet, of a package. Cubic feet can be calculated for rectangular packages by using the following equation: Length x Width x Height / 1728. Cubic feet can be calculated for soft packages by using the Length and Width, and looking up the sum in the Soft Pack pricing tier table. Cubic Pricing allows EasyPost customers to spend less on small, dense packages.

Service Levels

USPS has several service levels supported by EasyPost. Service levels have to do with both the speed and type of shipments. Each service level is detailed below. For reference, Girth is 2 times (Width + Height).

ServiceTransit TimeMax DimensionsMax Weight
First-Class Mail (Letters and Flats)1-3 daysLetters: 11-½" x 6-⅛" x ¼" (29 cm x 15 cm x 0.635cm) Flats: 15" x 12" x ¾" (38 cm x 30 cm x 1.9 cm)13 oz (368 g)
First-Class Package Service1-3 days22" x 18" x 15" (55 cm x 45 cm x 38 cm)15.99 oz (453 g)
Priority Mail2-3 daysCombined Length and Girth < 108" (274 cm)70 lbs (31 kg)
Priority Mail Express1-2 daysCombined Length and Girth < 108" (274 cm)70 lbs (31 kg)
Parcel Select Ground2-8 business daysCombined Length and Girth < 130" (330 cm) 70 lbs (31 kg)
Library Mail2-8 business daysCombined Length and Girth < 108" (274 cm)70 lbs (31 kg)
Media Mail2-8 business daysCombined Length and Girth < 108" (274 cm)70 lbs (31 kg)
First-Class Package International Service7-21 daysCombined Length and Girth < 108" (274 cm)64 oz (1814 g)
Priority Mail International6-10 business daysCombined Length and Girth < 108" (274 cm)70 lbs (31 kg)
Priority Mail Express International3-5 business daysCombined Length and Girth < 108" (274 cm)70 lbs (31 kg)

Predefined Packages

USPS has several predefined packages supported by EasyPost, linked below. Predefined packages are an easy way to classify and therefore price a package. With the EasyPost API, pick a predefined package that qualifies for your shipment (and sometimes add the weight) in your request and request rates. See sample request in our predefined package documentation.

USPS Labels

EasyPost supports both domestic and international USPS labels in the following format: PNG, PDF, ZPL, EPL2, and ASCII. Request or convert your file type of your labels using our Label API. Below are two test PNG Labels, one is an international label (left) and the other is a domestic label (right):

USPS International Label
USPS Domestic Label

USPS Pickups

USPS will pick up your package for free if you have one of following package types out for shipment:

  • Priority Mail Express
  • Priority Mail
  • First-Class Package Service
  • USPS Returns
  • International

Requests must be received by 2:00 AM CST in order to be picked up that day. After 2:00 AM CST, the USPS will pick up your packages during the next business day. Packages must be properly sealed and ready for shipment.

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