Integration scoped as orders out and nothing back
The most common shape is an integration that sends orders and receives a despatch confirmation, and nothing else. That leaves stock positions, adjustments, receipts and returns to portal logins and email, which means they are done irregularly and by whoever has time. Insist that the inbound flows are in scope from the beginning, because retrofitting stock reconciliation to a live relationship is considerably harder than including it, and the provider has less incentive to help once the contract is signed.
No agreed reconciliation or tolerance
Two stock ledgers will diverge. Without an agreed comparison frequency, an agreed tolerance and an agreed process for resolving a difference, divergence turns into a standing argument in which each side quotes its own system. Settle in the contract how often positions are compared, what constitutes a discrepancy requiring investigation, who investigates, and how an unresolved difference is ultimately written off and by whom.
Errors that cannot be attributed
A customer received the wrong item. Was the pick wrong, was the product data wrong, was the barcode duplicated across two products, or did the order arrive with the wrong code from your side? Without event level data on both sides, the conversation is unwinnable in either direction and the service level agreement is decorative. Capture enough detail at handover and at despatch to attribute an error to a cause, and report it monthly by category rather than as a single error rate.
Batch, serial and expiry treated as optional
For food, beverage, cosmetics, therapeutic goods, chemicals and anything with a recall exposure, the ability to identify which batch went to which customer is not a reporting nicety. If a recall becomes necessary you need it immediately and accurately, and reconstructing it from despatch records afterwards is slow and incomplete. Confirm that the provider’s system captures and returns batch, serial and expiry at the point of pick, and test that the data actually flows back before you rely on it.
Provider transition with no plan
Moving between providers means a stocktake at both ends, a freeze on despatch, in flight orders that must land somewhere, open purchase orders redirected, and two integrations running in parallel for a period. Businesses that treat it as a logistics exercise and leave the systems until last routinely lose a trading week. Plan the cutover as a systems project with a rehearsed sequence, a freeze window agreed with your channels, and a reconciliation at both ends before the old site is released.
Customer data sent beyond what is needed
A provider needs names, delivery addresses and contact details to deliver, which is a disclosure of personal information under the Privacy Act 1988 and the Australian Privacy Principles. Send only the fields required for fulfilment, agree in writing what they may do with the data, how it is secured and how long it is retained, and make sure a customer deletion request can be actioned in their systems too. Marketing consent flags and payment details should not cross the boundary at all.