Short answer
Inventory reconciliation periodically compares stock quantities in the ecommerce platform with the quantities the ERP says should be published, then reports or corrects differences. It catches drift caused by missed events, manual edits, failed updates, and timing gaps. Reconcile with a consistent calculation, account for orders in flight, correct cautiously with thresholds, and track drift over time as a health metric.
Inventory reconciliation is the process of comparing what an online store shows as available with what it should show according to the ERP, and resolving the differences. It is the audit that keeps continuous inventory sync honest.
Why stock drifts
Even well-built inventory sync drifts over time:
- Missed events during outages or deployments.
- Manual edits in the store admin.
- Failed updates that were never retried.
- Timing gaps: orders accepted by the store but not yet processed by the ERP.
- Mapping changes: new warehouses or SKUs not yet mapped.
How reconciliation works
- Extract current quantities from the store, per SKU and location. For large catalogs, bulk export APIs (such as Shopify’s bulk operations) are far more efficient than paging.
- Calculate the expected sellable quantity from ERP data, using exactly the same formula as the live sync, including in-flight order adjustments and safety buffers.
- Compare and classify differences: none, small, large, unmapped.
- Act: report, auto-correct small differences, and route large ones for review.
- Record results as metrics so drift can be tracked over time.
Correcting safely
- Use the same write path as the live sync, including compare-and-swap where the platform supports it.
- Set thresholds: automatic for small differences, review for large jumps.
- Avoid running corrections during peak sales periods, when quantities change rapidly.
- Log every correction with its reason and the before/after values.
Measuring drift
Track the number and percentage of SKUs with differences after each run. A stable, low drift rate shows the live sync is healthy; a rising rate is an early warning of a broken event path or mapping.
Summary
Inventory reconciliation compares store stock with ERP-derived expectations, then reports and corrects differences. It is essential even with real-time sync. Use consistent calculations, account for in-flight orders, correct cautiously, and monitor drift as a health metric. See inventory synchronization for the live-sync side.
Frequently asked questions
How often should inventory be reconciled?
Nightly is a common baseline, with more frequent checks for fast-moving items. The right frequency depends on how quickly drift causes overselling or lost sales.
Should reconciliation fix differences automatically?
Start with reports only. Once you trust the calculation, enable automatic correction for small differences and require review for large ones.
Why does drift happen if inventory sync is real-time?
Events get missed during outages, people edit stock manually in the store, updates fail validation, and orders in transit create timing gaps. Reconciliation is the safety net for all of these.
Sources and further reading
Platform-specific statements on this page were checked against these sources on . Vendor APIs change; confirm details in the current documentation before you build.
- [1] Shopify — manage inventory quantities and states — Shopify
- [2] Shopify bulk operations — Shopify
- [3] Shopify webhook best practices (reconciliation jobs) — Shopify
Related reading
- Guides How to Synchronize Inventory Between Shopify and an ERP Keep Shopify stock levels aligned with your ERP — choosing which quantity to publish, mapping locations, using compare-and-swap updates, and reconciling drift.
- Concepts What Is Scheduled Synchronization? How scheduled, batch-based synchronization works in integrations, how to design checkpoints and windows, and where it fits alongside event-driven updates.
- Concepts What Is Integration Monitoring? What integration monitoring covers, how it differs from application monitoring, the key metrics for ecommerce-ERP integrations, and how it prevents silent data loss.
- Guides How to Map Ecommerce Products to ERP Articles and SKUs Design product and variant mapping between an ecommerce platform and an ERP — SKU strategy, variants, bundles, units of measure, cross-references, and validation.