USPS Guide

The U.S. Postal Service (USPS) is the only delivery service that reaches every address in the nation: nearly 167 million residences, businesses, and Post Office Boxes. The Postal Service generally receives no tax dollars for operating expenses and relies on the sale of postage, products, and services to fund its operations.

This guide provides detailed information on utilizing USPS shipping with the EasyPost API, focusing on account setup, rates, label creation, pickups, tracking, and more.

Sign up for an EasyPost account to obtain a Test and Production API key. See Authentication and Key Management for more information.

Upon sign-up with EasyPost, users gain immediate access to Default Carrier Accounts, which can be enabled directly from the Dashboard. For additional carriers, EasyPost supports a Bring Your Own Account (BYOA) option for additional carriers. This requires users to register directly with the respective carrier.

1. Log in to EasyPost and navigate to Account Settings.

2. Select the Carriers tab.

3. Select the EasyPost Carrier Accounts tab.

4. Navigate to USPS Account in the list of carriers and select Create Account to complete the account creation process.

   

1. Register for a USPS account.
2. Input carrier-specific credentials within the Carrier Account Dashboard for comprehensive rate access. For more information, see Bring Your Own Account to EasyPost.

The API structure specified by EasyPost can also be used to add a USPS carrier account.

curl -X POST https://api.easypost.com/v2/carrier_accounts \
  -u "$EASYPOST_API_KEY": \
  -H 'Content-Type: application/json' \
  -d '{
  "type": "UspsAccount",
  "description": "UspsAccount",
  "carrier_account": {
    "credentials": {
      "address_city": "VALUE",
      "address_state": "VALUE",
      "address_street": "VALUE",
      "address_zip": "VALUE",
      "company_name": "VALUE",
      "email": "VALUE",
      "phone": "VALUE",
      "shipper_id": "VALUE"
    }
  }
}'

Download an EasyPost Client Library or utilize the REST API with cURL.

Examine the EasyPost Objects section to understand the API's structure, which is critical for constructing requests and interpreting responses.

Three USPS pricing tiers impact shipping rates:

• USPS Retail Pricing: The rate paid at a local Post Office or other retail location.
• USPS Commercial Pricing: Offers savings over USPS Retail pricing available to business shippers.
• USPS Merchant Discount Pricing: A special negotiated rate between EasyPost and USPS that allows EasyPost to provide discounts below USPS Commercial Pricing.

See the USPS Rate Chart for more details.

Cubic Pricing is based on package volume and is useful for small, dense packages.

USPS has several service levels supported by EasyPost, each with specific transit times and conditions.

USPS has several predefined packages supported by EasyPost. Predefined packages are an easy way to classify and price a package.

When using the EasyPost API, users should select a predefined package that matches the shipment's criteria and, if necessary, add weight to the request to obtain rates. The predefined package documentation provides detailed sample requests.

With EasyPost, the process for generating shipping labels for USPS is the same as generating them for any other carrier.

Review the Getting Started Guide for help generating a shipping label.

EasyPost supports both domestic and international USPS labels in the following formats:

• PNG
• PDF
• ZPL (may not be supported for letter and card label sizes)
• EPL2

Use the EasyPost Label API for file-type requests or conversions.

See the Customs Guide for more information.

Possible values for USPS shipping label sizes:

• 4x6 (default)
• 4x4
• 8.5x11
• 7x3 (Available when using predefined_package: Letter when First rate is purchased. See Predefined Packages)
• 6x4 (Available when using predefined_package: Card or Letter and when First rate is purchased. See Predefined Packages)

Shipments can have a variety of additional options that can be specified when creating a shipment. These options include custom messages that can be printed on labels.

{
  "options": {
    "print_custom_1": "printCustom1",
    "print_custom_2": "printCustom2",
    "print_custom_3": "printCustom3",
    "invoice_number": "INVOICE12345",
    "label_size": "4x6",
    "label_format": "PNG"
  }
}

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." EasyPost is in full compliance with all USPS HazMat guidelines. Users are responsible for specifying the type of HazMat included in each shipment.

• Extra services are restricted to only adult signatures or USPS Insurance.
• Refunds for Priority Mail Express are not available for HazMat if delivered or attempted within three days of mailing.

• Service indicator H for identification.
• HAZMAT - Surface Transportation Only below the return address for surface-only packages.
• 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 packaging documentation.

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.

See the table below for valid string values and descriptions of each HazMat type supported by USPS. For more information, refer to USPS Pub 52 Hazardous Material and Dangerous Goods Regulations.

USPS will pickup the following package types for free:

• Priority Mail Express
• Priority Mail
• Ground Advantage
• USPS Returns
• International

Request by 2:00 AM CST for same-day pickup. Packages must be properly sealed and ready for shipment.

EasyPost simplifies package tracking by offering two methods:

• Tracking with an existing number and carrier.
• Using a Tracker included with an EasyPost-purchased shipping label.

The service integrates webhooks for timely shipment updates. For detailed information on tracking methods, visit the Tracking Guide.

The Carrier Metadata endpoint can programmatically return information about USPS service levels, predefined packages, supported features, and shipment options.

Use this information to quickly integrate with USPS and make educated decisions about the mix of carriers for shipping needs. Additionally, the Carrier Metadata endpoint is available to retrieve comprehensive information about all carriers on the EasyPost platform, enhancing decision-making for carrier services.

In addition to the guidance provided in our Carrier Guides, EasyPost offers support to assist with FAQs, troubleshooting issues, and inquiries related to the EasyPost platform.

Please visit the Help Center for more information.

USPS offers public APIs called USPS Web Tools.

For questions about getting started with USPS through the EasyPost API please talk to a Shipping Expert or contact our Support team.