Whistl Developer Guide & API Credentials
This developer guide shows how to access Whistl shipping API via Postmen, and Whistl web service. See also the list of required API credentials / keys for Whistl integration.
Email Whistl sales representative and cc support@postmen.com Tell Whistl you need to obtain Whistl web service API credentials.
Whistl will provide testing credentials for Sandbox environment: Client Code, Site Code and Customer Number
Use the Whistl testing credential to generate a label via Postmen Sandbox environment. Send Whistl the sample label, together with request and response xml files.
Whistl will provide the production credentials for Whistl web services API: Client Code, Site Code and Customer Number

Read Whistl docs
Supported Whistl service types and service options
Postmen Whistl technical support: support@postmen.com
Get Whistl Developer Credentials
Email Whistl sales representative and cc support@postmen.com Tell Whistl you need to obtain Whistl web service API credentials.
Whistl will provide testing credentials for Sandbox environment: Client Code, Site Code and Customer Number
Use the Whistl testing credential to generate a label via Postmen Sandbox environment. Send Whistl the sample label, together with request and response xml files.
Whistl will provide the production credentials for Whistl web services API: Client Code, Site Code and Customer Number
Required Whistl API credentials

Whistl Developer Resources
Read Whistl docs
Supported Whistl service types and service options
Postmen Whistl technical support: support@postmen.com
Updated on: 20/06/2022
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