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.

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.

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).

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.

According to USPS, HazMat is any article or substance designated by the U.S. Department of Transportation as being capable of posing an unreasonable risk to health, safety, or property during transportation. In international commerce, HazMat is known as "dangerous goods." HazMat items include but are not limited to explosives, flammable and combustible materials, and radioactive materials. Interestingly, many electronic devices with lithium batteries are HazMat according to USPS. If you're unsure whether your shipment contains HazMat,USPS provides a helpful table of HazMat items on their website.

These are some of the key properties of HazMat shipments. More details can be found in USPS Pub 52.

• Extra services are restricted to only adult signature or USPS Insurance.

• Refunds for domestic Priority Mail Express are not be available for shipments containing HazMat if the item is delivered or delivery was attempted within three days of the date of mailing. This is because they may require different handling than those that do not contain HazMat.

• Shipping labels for HAZMAT packages will have additional content including the following (see the image below of a sample HAZMAT label):

  • a service indicator "H" for identification
  • the words "HAZMAT - Surface Transportation Only" below the return address for surface-only packages
  • the word "HAZMAT" after "USPS TRACKING #" above the tracking barcode.

• Some HazMat types are restricted from aircraft and will only return available ground rates.
• Shippers are responsible for other required HAZMAT markings and documentation for packaging.
• EasyPost will upload HAZMAT type electronic data to USPS.

Due to the complexity of HazMat regulations and how each carrier handles them differently, many HazMat types are limited to specific carriers. Therefore, to get rates from multiple carrier you will need to make a separate rate request using each carrier's specific HazMat identification type. Selecting a HazMat type supported by another carrier not listed below will result in no USPS rates returned.

The table below shows valid string values and descriptions of each HazMat type supported by USPS. Refer to USPS Pub 52 Hazardous Material and Dangerous Goods regulations.

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

• Priority Mail Express
• Priority Mail
• Ground Advantage
• 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.

• USPS Web Tools