Retrieve current inventory for each inventoryItemId and locationId combination using the inventoryLevel query or bulk operation for large catalogs
Compare on-hand quantities from your physical count sheet against the Shopify available quantities
For each discrepant location, call inventorySetOnHandQuantities mutation with the name set to available and the new quantity value
Include a reason string (such as correction or received) to maintain an audit log in Shopify's inventory activity feed
Verify the adjustment by re-querying inventoryLevel after the mutations and confirm changes are reflected in the Shopify admin inventory history
Known gotchas
inventorySetOnHandQuantities sets an absolute value, not a delta; using the wrong quantity overwrites the existing count entirely, so verify source data accuracy before calling
Inventory adjustments made while active fulfillment orders are committed can cause negative available quantities; check committed quantities before setting on-hand totals
Bulk inventory corrections using the Admin GraphQL bulk mutation endpoint are asynchronous; poll bulkOperationRunQuery status before assuming the job is complete
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