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Setting up USPS by Endicia for Shipping

USPS by Endicia provides real-time shipping quotes from USPS to shoppers on your storefront. USPS by Endicia is only available to stores that ship from the United States. This guide covers setting up and using USPS by Endicia for real-time shipping quotes.

For more information about buying postage and printing shipping labels with Endicia, see Printing Shipping Labels with USPS by Endicia.


Do I have to set up label printing? You don't need to set up label printing if you just want to use Endicia to serve real-time USPS shipping quotes.


Enabling USPS Real-Time Shipping Quotes

1. Go to Store SetupShipping.

2. Click Edit or Configure next to a shipping zone.

3. Scroll down to Real time shipping quotes, and click Connect next to USPS.

Connect button to the right of the USPS by Endicia shipping method

4. In the pop-up that appears, click Connect it here if you already have an Endicia account. Otherwise, fill out the account creation form to create a new account.

Endicia sign up form

5. Specify a Display Name, which is shown to shoppers on the cart and checkout pages. Select your Delivery Services and Packaging Types. Additionally, you have the option to Show the estimated delivery date, which will display how many business days a particular service will take.

Endicia settings

6. Click Submit to save your changes.

Should you need to change your service or package types, click Edit from the zone page. Toggle the ON/OFF switch to enable or disable this shipping method.

If you're using your own packaging (Parcel), in addition to weight we recommend adding physical dimensions (width, height, and depth) for your products. Some real-time shipping providers require these in order to provide your shoppers with an accurate shipping quote during checkout. Typically, the narrowest dimension should be set as the factoring dimension in your physical dimension settings.


Additional Settings

1. Click Edit next to USPS by Endicia.

Edit button highlighted next to the USPS by Endicia shipping method

You will see the following tabs:

Configure pop up


The Settings tab contains the following settings:

  • Display name
  • Show estimated delivery date
  • Delivery services
  • Packaging types


The Connection tab is where you enter your account information. It contains:

  • Account Number
  • Pass Phrase


The Quote tab lets you test your connection and get a quote. Enter your destination country, state, and zip code, followed by your package weight, value, and dimensions. Click Quote, and you will see a shipping quote for all valid services.

Postage Balance

The Postage Balance tab shows your current account balance on Endicia.

  • Current Postage Balance — the current balance on your Endicia account
  • Add to balance — by adding funds here, the credit card you have listed on your Endicia account will be automatically charged


The Passphrase tab allows you to change the passphrase you set up in your Endicia account. Enter the following information, then click Confirm.

  • Current passphrase
  • New passphrase
  • Confirm new passphrase

Privacy Policy

The Privacy Policy tab will have a link to the USPS privacy policy.

  • Account Number
  • Pass Phrase


USPS Support

The USPS support website provides many helpful resources, including refund and insurance claim information, and other frequently asked questions.

USPS Weight and Dimensional Limits

Package terms
  • Length — the longest edge of a package
  • Width — the second longest edge of a package
  • Height — the shortest edge of a package
  • Girth — (2 x width) + (2 x height)
  • Machinable — parcels that can be processed by Postal Service equipment

User-added image

Domestic Weight and Dimensional Limits
ServiceWeight LimitDimensional Limit
First-Class Mail13 ozMinimum: 6 in x ¼ in x 3 in (L x W x H)
Maximum: 22 in x 15 in x 18 in (L x W x H)
Priority Mail, Priority Mail Express, Media Mail, Library Mail70 lbsMaximum length plus girth must not exceed 108 in
Standard Post, Parcel Select70 lbsMaximum length plus girth must not exceed 130 in
International Weight and Dimensional Limits

Some USPS services have different weight limits when delivering internationally. Check the postal service’s listing of Country Price Groups and Weight Limits for more information on specific countries.

USPS’s website provides a Customer’s Guide to Mailing, which has helpful tips on packing and shipping best practices, and even offers free shipping supplies, including boxes, that they will ship to your home or business.

Service Specifics and Rate Calculation

The Postal Service provides a comparison of services on their site, which can help you decide which services are the best fit for you, your product and your customers. Standard Post and Media Mail are not available for international shipping. Generally, for shipments under 6 ounces, First-Class Mail offers the lowest cost solution.


Take note! There are some products, like ammunition, that are restricted and that the Postal Service won’t ship.

You can use the Postage Price Calculator to simulate shipments in order to see what each service would cost and get delivery time estimates.

There are several factors that can affect what a shipment will cost:

USPS Real-Time Quotes Common Issues

Symptom: Returned quotes on the storefront don’t match what is displayed on the USPS postage calculator.

Possible causes:

  • Depending on the size of the package, USPS could be assessing a fee using its dimensional weight or balloon weight. Packages that are larger than the length plus girth limits can be charged an oversized rate.

  • If you’re using our older USPS integration, and Package size is not set to “Large”, package dimensions aren’t submitted when requesting quotes, so if the package has a larger dimensional weight than the actual weight, the returned quote will be too low.

  • Physical dimensions aren't defined for the product. Some real-time shipping providers require these in order to provide your customers with an accurate shipping quote during checkout. Typically, the narrowest dimension should be set as the factoring dimension in your physical dimension settings.

Symptom: Certain services completely fail to return a quote.

Possible causes:

In this instance, it would trigger an error in the store logs when making the quote request. There’s no error reporting on the storefront for this, so there would just be the absence of a First-Class Mail quote.

  • The package might be exceeding the limits of that service. For example, if your product weighs 4 ounces, and a shopper adds 4 of them to the cart, the combined weight is 16 ounces, and would not qualify for First-Class Mail.

  • The origin zip code may be wrong or incomplete. Where possible, use the full nine-digit zip code for your origin address in the Shipping Manager.

  • The destination address or country may fall outside of that particular service's specific service area.

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