ShipStation API

The ShipStation API (formerly known as ShipEngine) is a multi-carrier shipping platform that lets your storefront quote, label, track, and validate shipments across dozens of parcel and LTL freight carriers through a single API key. Once connected, ShipStation API carriers appear alongside your native FedEx and UPS accounts in the Shipping Methods page and contribute live rates at checkout.

Use the ShipStation API when you want to offer carriers that PrintNow does not integrate with natively (USPS, DHL, regional carriers, LTL freight providers, etc.) or when you prefer to manage all of your carrier accounts through ShipStation's dashboard instead of individual carrier portals.

Signup & Account Setup

The general practice for your customers is to create a ShipStation API account directly on our website here: ShipStation API signup.

Once an account has been created, the customer will receive an email from a member of our team that is assigned to that account and can answer questions regarding the ShipStation API software and setup on our end. Feel free to share this guidance on how to generate ShipStation API credentials in their dashboard — this is something customers retrieve on their own. Be sure to clarify that they'll need the Production API key, as this is a common point of confusion for users.

From there, if the customer has questions regarding their ShipStation API account, they can contact their account rep — whom they will have gotten an email from at signup — or the ShipStation support team by emailing support@shipengine.com.

Configure ShipStation API

1. From your Unified Admin, go to Settings > Shipping Settings > Shipping Methods.
2. In the right sidebar, locate the ShipStation API Account panel. This panel only appears when ShipStation API is enabled for your storefront.
3. Paste your Production API key into the Api Key field.
4. Click Save.
5. Click Configure Parcel Carriers to choose which parcel carriers connected to your ShipStation API account should be enabled for rate calculations at checkout.
6. If LTL shipping is enabled for your storefront, click Configure LTL Carriers to set up freight carriers with service codes and lift gate options.
7. Click Refresh Rate Rules on the rate rules grid to fetch the newly enabled carrier services so they can be managed alongside your other shipping methods.

Settings

How Rating Works

When a customer reaches checkout, the storefront builds a rate request with:

1. The ship-from address resolved from your Shipping Locations (closest location by geocode, or the default).
2. The customer's ship-to address.
3. The package dimensions and weight resolved from the matching Package Types for each line item.

The request is sent to the ShipStation API, which fans it out across every parcel (or LTL) carrier you enabled in the Configure Parcel/LTL Carriers dialogs. Each returned service is shown to the customer as a shipping option, subject to the rate rule's status mode, handling fee, and any free-shipping overrides. Rates from ShipStation API are rendered alongside native FedEx, UPS, and fixed-rate options in the same list.

LTL Freight

The ShipStation API supports Less-Than-Truckload freight carriers for oversized shipments. Freight rating kicks in automatically when any line item in the cart resolves to a Pallet or Skid package type (see Package Types). When LTL is enabled for your storefront:

• The Configure LTL Carriers button appears in the ShipStation API panel.
• Each LTL carrier is configured with service codes and optional accessorials (for example, lift gate delivery).
• Freight rates returned by the ShipStation API are displayed alongside parcel options at checkout, with handling fees and free-shipping flags applied in the same way.

Combining ShipStation API LTL with PrintNow's own FedEx Freight integration is supported — enable whichever mix of carriers matches your negotiated pricing.

Address Validation

When a ShipStation API key is saved, address validation at checkout is routed through ShipStation instead of Google Address Validation, regardless of whether a Google key is also set. ShipStation validation takes priority and can flag incomplete or undeliverable addresses before the order is placed. See Google Address Validation for the full priority order.

Associations

Print Store

Related Pages

• Shipping Methods — enter the API key and manage the resulting rate rules
• Shipping Locations — ship-from addresses used as the origin for ShipStation API rate requests
• Package Types — dimensions and weights sent to ShipStation API, including Pallet/Skid packages that trigger LTL freight
• Google Address Validation — the fallback address validator used when ShipStation API is not configured