Why your online store and warehouse should show the same stock

A warehouse may contain ten units while only seven are available to sell. Two might already be reserved and one awaiting inspection after a return. Connecting the store to the warehouse starts with agreeing what each number means.

Distinguish physical and sellable stock

Define quantities on hand, reserved, unavailable and available for sale. Decide whether incoming stock can be sold before receipt and how the delivery expectation will be shown. A customer should not see “In stock” when the promise actually depends on an unconfirmed supplier delivery.

Agree which system owns stock movements and which system displays the selling availability. Avoid allowing several applications to overwrite the same quantity independently without a clear reconciliation rule.

Reserve at a defined point

Decide when an order reserves stock: on submission, payment confirmation or another documented step. Explain how long unpaid orders hold quantities and when those reservations expire.

Cancellation, partial dispatch and returns need matching rules. A returned product should not automatically become sellable if it still needs inspection. For variants and bundles, confirm exactly which component quantities change.

Plan for delays and failed updates

Ask how quickly changes move between the warehouse and store, and how failed updates become visible. If the final unit sells in a physical shop, the online listing needs an appropriate response. A buffer may be useful where instant synchronisation is not possible, but it should be a deliberate policy.

Test the complete sequence with a sample product: receipt, online order, reservation, dispatch, cancellation and inspected return. Add a test for two orders competing for the last unit and for a temporary connection failure.

Use a regular discrepancy report showing product identifier, expected quantity, actual quantity and the last update. The aim is not merely matching numbers on two screens. It is making a delivery promise the business can keep and identifying problems before customers discover them.