This article describes the concept of External method id in Ingrid: its logic and the usage.
What is an External method id?
External method id is a unique carrier product identifier in a Merchants WMS or TA system. 
Image 2 - Example of external method id is equal to P19NO
Setup Guidance
Background
In your 3PL, WMS - Warehouse Management System or TA - Transport Administration systems a carrier service is defined with a special code/id. Just like in Ingrid every carrier product is defined with a product code seen below a product name. Fx, UPS Standard internal Ingrid code is ups-std, see in the screenshot below.
In order to link a chosen shipping option in Ingrid with the shipping method in your WMS the external method id is used.
There you have to define a unique identifier of a particular carrier service from your WMS/TA (depending on the booking flow).
Eventually external method Id will land in the delivery information of the order.
Image 2 - External method id in the Delivery information of Ingrid Transport Order
External method id is a mandatory setting to define, otherwise the booking information flow could be unpredictable.
Setting External method id in Ingrid Platform
Steps:
1. Go to Delivery Checkout > Regions > Specific region > Specific carrier product
2. Define an External method id.
