Carrier Service not contacted if product assigned to a fulfillment service

Shopify Partner
9 0 1



We have an app that creates a Carrier Service and a Fulfillment Service. The app is running with around 50 users every day without any issue.


However, today we installed the app on a new customer's shop, created the carrier service and fulfillment service. First we did not assign the products to the fulfillment service, and orders were placed on the shop using our carrier service's shipping rates. Then, we edited the products to say they were "Stocked at" our fulfillment service. At this moment, the checkout page (rates step) shows a red error saying the cart has been updated and the items cannot be shipped to my address, and that I should remove the items to finalize the order.

When looking at our logs (server side of the carrier service API), we can see that Shopify did not even try to fetch the rates. The API call has never been fired.


When we remove the fulfillment service from the products, shipping rates are now fetched from the carrier service and orders can be finalized.


What is this behavior? How can a fulfillment service have any effect on whether Shopify decides to fire the API request to fetch shipping rates from the carrier service?


Thanks a lot!

Reply 1 (1)

Shopify Staff
129 15 24

Hey @victor75 - great question!


In order for products to be shipped out from a specific Fulfillment Service "location", that service would have to be associated with its own shipping zone (and the associated rates) which are set up through the merchant's shipping and delivery settings.


At the bottom of the shipping profile menu, your merchant would likely see something like this:



After selecting your fulfillment service from the options and assigning it to a specific shipping zone, they could then add the rates from your carrier service, which would allow it to be selected as an option at checkout. 


There is a way to automate part of this process through GraphQL , if you wanted to take a look at integrating this method with your app. Some useful example mutations and more information about how delivery profiles work can be found in that documentation - great stuff there if you haven't checked it out yet. 


Hope this clarifies the requirements around Fulfillment Services/Shipping rates and gives you some next steps going forward. If you encounter any further issues after confirming the requirements mentioned above are met, just let us know, happy to dig into this further if need be. 



Alan | API Support @ Shopify
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