Shopify POST draft order not respecting passed shipping_line

Shopify Apps

Topic summary

Draft order API calls to create/update a shipping_line are ignored when a store has “Carrier and app rates” enabled, resulting in shipping_line: null in responses. Manual addition in the Shopify admin still works.

Key conditions:

  • Problem appears only with carrier/app-calculated rates (e.g., enabling a UPS Next Day Air rate via a shipping app). Disabling these rates restores expected API behavior.
  • The API accepts shipping_line only when custom is set to true; when custom:false, it’s ignored under these conditions.

Impact:

  • Breaks app workflows that rely on setting specific shipping rates on draft orders. Multiple stores are affected.

Technical note:

  • Example payload shows shipping_line with handle/title/price and custom:false; response returns shipping_line: null. This behavior affects both create and update endpoints in the Admin REST API.

Timeline:

  • Worked on Oct 20; stopped working sometime after Nov 8 (no orders tested between those dates).

Workarounds:

  • Set shipping_line.custom:true, or disable “Carrier and app rates” (not feasible for many).

Status:

  • No official Shopify response yet; support tickets reported. Issue remains open.
Summarized with AI on January 3. AI used: gpt-5.
5

Same issue here.

I can confirm that it worked correctly in the end of October as we just did extensive testing and launch of this feature.

Everything was working on 20th of October and it stopped work after 8.11. We haven’t had any orders in between, so I am not sure exact date, but it is in between them.