Quick answer
A bundle is only available while every component has enough stock. Kitforge calculates max sellable quantity, refreshes on inventory webhooks, and validates checkout to prevent overselling.
- One OOS component can zero a kit.
- Webhooks keep counts fresh.
- Test checkout at low stock.
- 3PL needs expanded child SKUs for picks.
Why bundles oversell without validation
Discount-only apps may ignore component depletion. Kitforge blocks checkout when max sellable is exceeded.
A kit with five units of component A and one unit of component B sells at most one bundle when B is the bottleneck.
The max sellable formula
For each component: floor(available_inventory ÷ quantityConsumed). Bundle max is the minimum across components. Kitforge recalculates on inventory_levels/update webhooks.
Multi-location inventory
Confirm which location drives online availability in your Shopify setup. Kitforge snapshots should match the location your storefront sells from.
Pre-campaign inventory audit
Before email or paid traffic, identify the lowest-stock component in the kit and set alerts. One OOS SKU zeros the entire offer.
Final recommendation
Treat bundle inventory as a system — Kitforge automates the math merchants often do in spreadsheets.
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
Does FBT use the same rules?
FBT checks per add-on availability; fixed kits use max sellable across components.