How it works
An OMS pulls orders from storefronts, marketplaces, wholesale portals and point of sale into one queue. It decides which warehouse or store fulfills each line, reserves stock, sends shipments to a warehouse or 3PL, pushes tracking back to the channel and handles returns. It sits between commerce channels and inventory and finance systems, and often overlaps with the ERP.
Example
An order from Amazon and one from Shopify for the same SKU both land in the OMS. It routes one to the East Coast 3PL and one to the brand's own warehouse, based on stock and distance.
In integrations
Order data is messy because every channel models it differently. The Unify Orders API is designed to bring orders, line items, fulfillments, refunds and payouts into one schema across storefronts and marketplaces, with fulfillment write-back where the channel allows. For commerce software, order data is usually the first integration customers ask for and the hardest to keep consistent, because every channel models taxes, discounts and refunds differently.