Shopify Functions
Shopify Fulfillment Constraints
Control where Shopify orders ship from with fulfillment constraint Functions: keep items together, stop costly split shipments and restrict items to locations.
Multi-location stores all hit the same problem. Shopify will split an order across locations when it needs to, and some orders should never be split: a matched set arriving in two boxes, a frozen item sent from a store without a freezer, a $20 order shipped as two parcels. Fulfillment constraint Functions let you set those rules at checkout.
Two kinds of rule
- Ship from the same location. Items that must travel together, like a set, a pair or a bundle, can only be fulfilled from one location that has all of them.
- Ship only from these locations. Products that need special handling, like cold storage, hazardous materials or oversized goods, can only come from the locations set up for them.
Rules from your operations, not the API
We start with how your warehouses and stores actually work: which products need special handling, which locations can handle them, and when a split shipment costs more than it earns. Then we encode those rules, driven by product and location metafields, so your team can keep them current as locations and ranges change.
Plan the edge cases
If a cart cannot be fulfilled within the rules, Shopify stops the checkout with an out-of-stock message rather than showing shipping options. We map those cases with you before launch, so a rule never quietly blocks sales you wanted.
Works with order routing
Constraints decide which locations are allowed. Order routing decides which allowed location is best. Together they give you control over where every order ships from.
What we build
Ship-together rules
Make items that belong together, like a set or a matched pair, ship from one location.
Location restrictions
Limit products to the locations that can handle them, such as cold storage or a freight dock.
Fewer split shipments
Stop low-value orders splitting into several parcels that cost more than the margin.
Planned edge cases
Decide what happens when a cart cannot meet the rules, before a customer finds out.
Questions, answered
What is a fulfillment constraint Function?
It tells Shopify which locations may fulfill the items in a cart. It can require items to ship from the same location, or limit them to a list of allowed locations. A store can run up to 25 of them.
What happens if no location can meet the rule?
Checkout cannot complete, and the customer sees an out-of-stock message instead of shipping options. That is why we design the rules and your stock setup together.
How is this different from order routing?
Constraints set hard limits on where items can come from. Order routing ranks the allowed locations to pick the best one. Many multi-location stores use both.
Do we need Shopify Plus?
For a custom fulfillment constraint Function built just for your store, yes, as with any custom app that uses Functions. Stores on other plans can use public apps built on the same API.
Related services
Order Routing
Custom rules that decide which location fulfills each order, on Shopify Plus.
Learn moreBundles and Add-ons
Product bundles, kits and paid add-ons that stay correct through cart, checkout and fulfillment.
Learn moreDelivery and Shipping Customization
Control which delivery and shipping methods show at checkout, and how they are named and ordered.
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