LSO Guide

Lone Star Overnight (LSO) is a leading regional parcel carrier offering a full selection of Ground and Express shipping services to ecommerce merchants, fulfillment centers, and online sellers.

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


Account Registration

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

Note: Negotiated rates are only available in Production mode.

Carrier Setup

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. This requires users to register directly with the respective carrier.

LSO Shipper Account Registration

  1. Register or log into the LSO website, ensuring a valid payment method is on file.
  2. Log into EasyPost and navigate to Account Settings > Carriers.
  3. Select the Add Carrier button at the top of the screen and choose LSO.
  4. Add the following LSO credentials:
    1. Production Account Number
    2. User Name
    3. Password
  5. Start purchasing labels through the EasyPost shipping API.

LSO Account via API

The API structure specified by EasyPost can also be used to add the LSO carrier shipper account.

curl -X POST \
  -H 'Content-Type: application/json' \
  -d '{
  "type": "LsoAccount",
  "description": "LsoAccount",
  "carrier_account": {
    "credentials": {
      "account_number": "VALUE",
      "password": "VALUE",
      "username": "VALUE"
    "test_credentials": {
      "account_number": "VALUE",
      "password": "VALUE",
      "username": "VALUE"

Software Requirements

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

Documentation Review

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


LSO is a Live Rating integration, enabling real-time rate retrieval for shipments created via EasyPost. Rates are guaranteed valid for a minimum of 5 minutes.

  • When creating a shipment, EasyPost requests LSO for shipment rates specific to the user's LSO account.
  • The rates provided are directly from LSO and tailored to the user's specific account details.
  • In cases of discrepancies or incorrect rates, users are advised to contact their LSO account representative.
  • The representative can then update the rates in LSO's database to ensure user account accuracy.

Service Levels

Transit Time
Max Dimensions (inches)
Max Weight (ounces)

Coverage Area

Map indicating LSO coverage area

Predefined Packages

There are no predefined packages for LSO.

Generating Shipping Labels

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

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

Void Labels

LSO allows for voiding labels as long as the shipment is still in pre_transit.

  1. Navigate to the EasyPost Dashboard → Shipments.
  2. Select Details.
  3. Select Refund.

Alternatively, this can be done via API call hitting the /refunds endpoint; see the Refunds section of the EasyPost API docs.

LSO does not allow the voiding of labels. Please contact EasyPost support for refunds.

Hazardous Materials (HAZMAT)

LSO does not handle shipments of dangerous goods or hazardous materials. For detailed information, please review the LSO Service Guide.


Pickups with LSO are free of charge and can be scheduled in two ways (Please note that a 24-hour notice is required to set pickups):

  1. Schedule a pickup via EasyPost’s Pickup API.


  2. Schedule pickups by calling LSO customer service at 512-872-6900. Let the agent know you are an EasyPost customer and have the following information ready:

    • Pickup address
    • Special instructions: gate code, etc.
    • Commercial or residential location
    • Contact name and phone number
    • Time packages will be ready - please allow a 2 hour window (minimum)
    • Open time and latest pickup time (e.g., no later than 4 PM)
    • Number of packages shipping per day
    • Type of package: Poly, box, standard dimensions
    • Service type: Express, Ecommerce, or Ground service


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.

Additional Resources

Carrier Metadata

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

Use this information to quickly integrate with LSO 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.

Support and Troubleshooting

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.

Talk to a Shipping Expert

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