If you want to send an order from a non-Amazon channel to be fulfilled by FBA, and wish to specify the shipping type, then the shipping priority used by the FBA center will be based on three keywords in the names of Linnworks Postal Services:

- Standard
- Expedited
- Priority

If the Linnworks postal service name contains any of these keywords, then FBA will know that the service they need to use should be either Standard, Expedited, or Priority. For example, a service with the name "International Priority Shipping" contains one of these keywords, so Amazon FBA will use the Priority service when they ship the item.

You can either set the shipping service manually for an order, or map the services in the channel shipping service mapping screen to have the correct service picked up automatically, or set up a rule in Rules Engine.