Whistl Guide

Whistl offers domestic and international shipping solutions for shipments originating in the UK. Whistl provides efficient and reliable delivery services, ensuring prompt transportation of parcels and documents to their intended destinations. With a strong network and advanced tracking technology, Whistl offers customers a seamless shipping experience with end-to-end visibility and exceptional customer support.

This guide provides developers an overview of shipping services that Whistl offers and the service codes that you will use to create Whistl shipments.

Connect Your Account

ShipEngine API allows you to connect your Whistl accounts programmatically without logging in to the ShipEngine API dashboard. This is useful if you have wrapped a custom UI around the ShipEngine API toolset and want to add or disconnect existing carrier accounts without exposing your end users to the API dashboard.

These APIs can be used in parallel with the ShipEngine Partner APIs to programmatically create new ShipEngine users, and then connect existing Whistl accounts all via the API without logging into a dashboard. Together these APIs empower you to completely white-label the ShipEngine experience for your end users.

Continue below for instructions on how to programatically connect Whistl using the ShipEngine API.

For instructions on connecting Whistl via the ShipEngine dashboard, go to our Whistl help article.

nicknameThis is a nickname for you to identify the carrier account in ShipEngine.string, required
passwordPasswordstring, required
accountAccount Numberstring, required
departmentDepartment Numberstring, required
tracking_api_keyTracking API Keystring, required

Example POST Call

POST /v1/connections/carriers/Whistl

POST /v1/connections/carriers/Whistl HTTP/1.1
Host: api.shipengine.com
Content-Type: application/json
"nickname": "My Whistl Account"
"password": "pa55word",
"account: "1234567",
"department": "89101112",
"training_api_key": "your_training_api_key",

Example POST Response

Your account will now appear in your carriers list with an assigned carrier_id that you will specify when creating Whistl shipments.

"carrier-id": "se-1234567"

Whistl Service Details

ServiceTypeService API Codes
Insight Large LetterDomesticwhistl_insight_large_letter_domestic
Insight PacketDomesticwhistl_insight_packet_domestic
Insight Large LetterInternationalwhistl_insight_large_letter_international
Insight PacketInternationalwhistl_insight_packet_international


NameAPI CodePackage Attributes
Parcelwhistl_packageDomestic, International

Return Services

Return services not supported for this carrier.

Adding Shipment Insurance

Whistl supports adding insurance to your shipments. Review the Parcel Insurance page for details on adding shipment insurance with ShipEngine.

Additional Features

Whistl supports the following additional features:

Customs FormsCustoms forms are printed directly onto the label instead of a separate document.

To ensure you always have the most up-to-date information, use the List Carrier Advanced Options call.

You are now ready to create shipments using Whistl via ShipEngine!