About USPS service methods

Shipium supports use of USPS service methods via USPS (Direct), EasyPost, Endicia, and Pitney Bowes. This document includes guidance for configuring your account to use USPS Direct service methods and for special use cases such as passing particular packaging types to the carrier in your calls to our APIs.

USPS Direct

Account requirements

To start using USPS Direct service methods within the Shipium platform, you'll need to ensure your account is authorized to interact with USPS's APIs.

A USPS business account is required to use the USPS Direct service methods. You'll need to provide your:

• company name;
• contact name; and
• contact email address.

You also can create a business account and generate a Mailer ID for label generation via the USPS Customer Onboarding Portal: https://cop.usps.com.

If you already have a USPS business account, you should reach out to your USPS account representative for USPS API onboarding support.

Configure USPS Direct for your account

To set up a carrier contract for USPS Direct, you'll need to access the Shipium Console and follow instructions for adding a carrier contract to a fulfillment context. If your organization doesn't use fulfillment contexts for configuration, you can use the fulfillment configuration workflow.

For either approach, once you reach the step to edit or add a carrier account for USPS Direct, you'll be asked to enter credentials required by USPS, in addition to the fields Shipium requires. All fields are required unless noted as optional.

• Credentials. You'll select USPS Direct Standard Credentials from the dropdown menu.
• USPS Direct Consumer Key. Your USPS account Consumer Key
• USPS Direct Consumer Secret. Your USPS account Consumer Secret
• USPS Direct CRID. Your USPS account Customer Reference/Registration ID
• USPS Direct MID. Your USPS account Mailer ID
• USPS Direct Manifest MID. Your USPS account Mailer ID for manifesting
• USPS Direct Account Number. Optional but required if not providing a permit number and permit ZIP. Your USPS account number; you must provide either an account number OR a permit number and permit ZIP.
• USPS Direct Permit Number. Optional but required if not providing an account number. Your USPS permit number; you must provide either an account number OR a permit number and permit ZIP.
• USPS Direct Permit ZIP. Optional but required if providing the USPS Direct Permit Number. The ZIP code associated with your permit number; you must provide either an account number OR a permit number and permit ZIP.
• USPS Direct Consumer Key (Test Mode). Your USPS account Consumer Key for test mode
• USPS Direct Consumer Secret (Test Mode). Your USPS account Consumer Secret for test mode
• USPS Direct CRID (Test Mode). Your USPS account Customer Reference/Registration ID for test mode
• USPS Direct MID (Test Mode). Your USPS account Mailer ID for test mode
• USPS Direct Manifest MID (Test Mode). Your USPS account Mailer ID for manifesting for test mode
• USPS Direct Account Number (Test Mode). Optional but required if not providing a permit number and permit ZIP. Your USPS account number for test mode; you must provide either an account number OR a permit number and permit ZIP.
• USPS Direct Permit Number (Test Mode). Optional but required if not providing an account number. Your USPS permit number for test mode; you must provide either an account number OR a permit number and permit ZIP.
• USPS Direct Permit ZIP (Test Mode). Optional but required if providing the USPS Direct Permit Number. The ZIP code associated with your permit number for test mode; you must provide either an account number OR a permit number and permit ZIP.

Shipping options with USPS Direct

Packaging types

Priority Mail Flat Rate®

USPS Priority Mail Flat Rate is a flat-rate shipping option that lets your organization ship packages that weigh 70 pounds or less to anywhere in the U.S. for a fixed price. You can find more details about this shipping method in USPS's Priority Mail documentation. Shipium supports selection of the Priority Mail Flat Rate shipping method.

To use the USPS Priority Mail Flat Rate shipping method, you'll first need to set up a carrier contract for the USPS Priority Mail Flat Rate in the Shipium Console.

Configure USPS Priority Mail Flat Rate for your account

To start using USPS Priority Mail Flat Rate within the Shipium platform, you'll need to set up your account in the Shipium Console to include the USPS Priority Mail Flat Rate service method. You can find instructions for establishing a fulfillment context for your organization and attaching a carrier service method and rate to that context in the Fulfillment Contexts documentation.

Specifically, once you have configured a fulfillment context with an origin (or fulfillment center), you'll follow the guidance in the Carrier Contracts documentation to establish carrier contracts, accounts, and rates. The carrier rates configuration is where you'll select the USPS Priority Mail Flat Rate service method from a dropdown menu, as shown in the following screenshot.

After completing this configuration, you can designate USPS Priority Mail Flat Rate as your shipping method.

Designate USPS Priority Mail Flat Rate as your shipping method

USPS Priority Mail Flat Rate allows you to use designated packaging and pay one flat rate. The maximum allowed weight is 70 pounds.

To use USPS's packaging for the Priority Mail Flat Rate, you'll need to designate the type of USPS Priority Mail Flat Rate packaging that you wish to use. The following is a snippet of a JSON request call to Shipium's APIs. The minimum required fields for successfully selecting a USPS Priority Mail Flat Rate delivery method are included in the sample request and are defined in the table below. These fields are included in the shipmentParameters or multiParcelShipmentParameters of the call.

"packagingType": {
        "packagingMaterial": "usps_large_box"
      },
      "totalWeight": {
        "weightUnit": "lb",
        "weight": 0.5

Letter mail

If you'd like to send letter mail via USPS Direct's first-class mail service, you'll need to include a value of letters as the type of packaging material when using USPS's Priority Mail or Priority Mail Express service method. You'll also need to specify one of the supported service methods in your call. Size and weight restrictions apply:

• Maximum dimensions of 11-1/2 inches long, 6-1/8 inches high, and 1/4 inch thick
• Maximum weight of 3.5 ounces

In some instances, letter mail may qualify for USPS's Ground Advantage service method. You can find more information in the Letter Mail with Ground Advantage Service Method section.

The following is a snippet of a JSON request call to Shipium's APIs. The minimum required fields for successfully selecting the letter mail service method are included in the sample request and are defined in the table below. These fields are included in the shipmentParameters or multiParcelShipmentParameters of the call.

{
  ...
"shipmentParameters": {
    ...
   "packagingType": {
        "packagingMaterial": "letters"
      },
        "totalWeight": {
           "weightUnit": "oz",
           "weight": 0.5
        },
  ...
  "carrierServiceMethodAllowList": [
    "usps-direct-priority-mail-service-method",
    "usps-direct-priority-mail-express-service-method",
    "usps-direct-priority-mail-international-service-method",
    "usps-direct-priority-mail-express-international-service-method"
    ],
  ...
}

Letter mail with Ground Advantage service method

USPS Ground Advantage typically is designated for shipping packages and certain types of large or irregular mail, not standard letters. However, letter mail could qualify for Ground Advantage based on its size, shape, and rigidity. When the following conditions are met, the item is treated as a package and it qualifies for Ground Advantage:

• Dimensions exceed limits. The mail piece is longer than 11-1/2 inches, taller than 6-1/8 inches, or thicker than 1/4 inch.
• Rigidity. The envelope is rigid (e.g., contains cardboard or another stiffener) and does not bend.
• Non-uniform thickness. The envelope is lumpy or contains items that make it uneven in thickness.
• Shape. The piece is not rectangular or has corners with a radius greater than 1/8 inch.

The following table summarizes which letter types might qualify for Ground Advantage. Letter mail that meets standard letter size and thickness requirements cannot be sent via Ground Advantage. It must be sent using First-Class Mail or other letter-specific services, as described in the previous section.

✳️ A standard flexible letter has a minimum length of 5 in and maximum length of 11-1/2 in; minimum height of 3-1/2 in and maximum height of 6-1/8 in; and minimum thickness of 0.007 in and maximum thickness of 1/4 in.

USPS via Endicia

Shipping options with USPS via Endicia

Packaging types

Letter mail via Endicia

If you'd like to send letter mail using USPS's first-class mail service via Endicia, you'll need to include a value of envelope as the type of packaging material and select a Priority Mail or Priority Mail Express service method. You'll also need to specify one of the supported service methods in your call. Size and weight restrictions apply:

• Maximum dimensions of 11-1/2 inches long, 6-1/8 inches high, and 1/4 inch thick
• Maximum weight of 3.5 ounces

In some instances, letter mail may qualify for USPS's Ground Advantage service method via Endicia. You can find more information in the Letter Mail with Ground Advantage Service Method via Endicia section.

The following is a snippet of a JSON request call to Shipium's APIs. The minimum required fields for successfully selecting the letter mail service method are included in the sample request and are defined in the table below. These fields are included in the shipmentParameters or multiParcelShipmentParameters of the call.

{
  ...
"shipmentParameters": {
    ...
   "packagingType": {
        "packagingMaterial": "envelope"
      },
        "totalWeight": {
           "weightUnit": "oz",
           "weight": 0.5
        },
  ...
  "carrierServiceMethodAllowList": [
    "usps-priority-mail-service-method",
    "usps-priority-mail-express-service-method",
    "usps-priority-mail-international-service-method",
    "usps-priority-mail-express-international-service-method"
    ],
  ...
}

Letter mail with Ground Advantage service method via Endicia

USPS Ground Advantage typically is designated for shipping packages and certain types of large or irregular mail, not standard letters. However, letter mail could qualify for Ground Advantage when shipping with Endicia based on its size, shape, and rigidity. When the following conditions are met, the item is treated as a package and it qualifies for Ground Advantage:

• Dimensions exceed limits. The mail piece is longer than 11-1/2 inches, taller than 6-1/8 inches, or thicker than 1/4 inch.
• Rigidity. The envelope is rigid (e.g., contains cardboard or another stiffener) and does not bend.
• Non-uniform thickness. The envelope is lumpy or contains items that make it uneven in thickness.
• Shape. The piece is not rectangular or has corners with a radius greater than 1/8 inch.

The following table summarizes which letter types might qualify for Ground Advantage. Letter mail that meets standard letter size and thickness requirements cannot be sent via Ground Advantage. It must be sent using First-Class Mail or other letter-specific services, as described in the previous section.

✳️ A standard flexible letter has a minimum length of 5 in and maximum length of 11-1/2 in; minimum height of 3-1/2 in and maximum height of 6-1/8 in; and minimum thickness of 0.007 in and maximum thickness of 1/4 in.

Resources

Your Shipium team member is available to help along the way. However, you might find these resources helpful:

• Terms and Definitions

• Troubleshooting Guide

• Contact Shipium Support