Magento MSI: “in stock” but not salable

Quantity versus salable quantity

Quantity is what the source says is on the shelf. Salable quantity is quantity minus reservations — stock held by orders that are placed but not yet shipped or cancelled. Add to cart checks salable quantity.

The inventory documentation explains sources, stocks and reservations. The key point for the checkout: if reservations are wrong, what the customer sees and what they can buy disagree.

How it drifts

Reservations are compensated when orders are shipped, cancelled or refunded, partly through queue consumers. If consumers stop, or an import writes quantity directly, or an ERP integration bypasses MSI, reservations pile up and salable quantity falls to zero while quantity looks healthy.

The opposite happens too: stale indexes show products as available when they are not, and the error appears at add to cart.

Keeping it honest

Make sure consumers and cron run, use MSI-aware imports and integrations, and use the inventory reservation CLI commands to find and fix inconsistencies.

For monitoring, pick a test product with plenty of stock and check add to cart on a schedule. A PRODUCT or CART failure on a product that has stock is often the first sign of reservation drift.

Check your own store now with the free Magento checkout test: it walks the checkout in a real browser, Luma or Hyvä, and shows the step where it stops.