Quick answer
KitForge disables bundle add-to-cart when components cannot fulfill the offer. Default outOfStockBehavior is disable_add_to_cart when max sellable quantity hits zero or a required variant is unavailable.
- Disabled ATC usually means inventory math, not a broken widget.
- Four out-of-stock behaviors change UX — pick intentionally.
- Check all components when one SKU hits zero.
- Inventory webhooks refresh max sellable quantity automatically.
Why disable is safer than hide
Disabling ATC preserves merchandising visibility while preventing a frustrating checkout failure. Hiding removes the offer entirely when any rule triggers.
Location-aware inventory
KitForge snapshots per-location availability. A component may show in stock on the product page but be unavailable at the fulfilling location.
Final recommendation
Treat a disabled bundle button as inventory signal. Fix stock or adjust bundle composition before overriding behavior.
If you want this kind of offer to feel native to the buying journey, Kitforge Bundles is built around that exact problem: turning related Shopify products into clearer bundle offers before the shopper reaches checkout.
FAQ
Can I allow backorder on bundles?
allow_backorder is supported in inventory policy settings. Confirm your 3PL can fulfill before enabling.