When stock counts don't sync between Dynamics 365 and your sales channels, you pay for it in cancellations, refunds, and margin that never shows up on a report.
You sold 40 units on Amazon over the weekend. The warehouse had 31. Now someone spends Monday morning canceling orders, and your seller metrics take the hit for a problem that started in the back office.
Most teams treat overselling as a customer service issue. The bigger cost sits in places nobody adds up. You eat the marketplace fees and the refund. You pay to expedite stock from another site to save the order. Amazon watches seller cancellations closely, so a rising cancel rate also puts your account health at risk.
Then there's the quieter fix. To stop overselling, many teams hold back a buffer and list fewer units than they have. That protects the account, but it also leaves sales on the table every day the buffer sits on the shelf.
We covered connector options and setup in our earlier post, Amazon and Shopify ERP Integration. This post is about why the counts drift and what it costs when they do.
The pattern we see is simple. Amazon, Shopify, your B2B portal, and your phone orders all draw from the same shelf, but each one sees a different number. A legacy ERP exports stock once a night, or someone uploads a spreadsheet each morning. Between those updates, every channel keeps selling.
This gap is more common than most people think. In a Deloitte Digital survey of 530 U.S. B2B executives, only 45% said they were integrating their ecommerce technology with a cloud ERP. Buyers notice. In Sana Commerce's 2025 B2B Buyer Report, 81% of buyers said outdated systems and inaccurate data got in their way, and 28% said wrong stock levels kept them from ordering online.
Dynamics 365 Business Central includes a Shopify connector out of the box. BC stays the system of record and pushes stock levels to Shopify through the job queue. Microsoft suggests a sync every 15 to 30 minutes, which is a major improvement over once a night.
Two settings matter most.
First, pick how stock is calculated. "Free Inventory" sends what's on hand minus reserved quantities, while "Projected Available Balance at Today" also subtracts sales orders due to ship.
Second, use a location filter so only the warehouses that actually ship online orders feed the shop.
Amazon works differently. Business Central doesn't include a native Amazon connector, so that link usually runs through BC's REST APIs or OData web services, either with a partner app or a custom integration. Microsoft recommends the REST APIs as the preferred route for new work. Whichever path you choose, the rule is the same: every channel should get its number from the same calculation in BC.
In Dynamics 365 Finance & Supply Chain Management, on-hand inventory updates as warehouse work is registered, so the number you publish reflects the floor. That matters when you ship from several warehouses and sell across many channels.
If you need every order routed to the best location automatically, raise it early in discovery. Automated routing rules aren’t standard on day one, so they belong in the scope conversation, not as a surprise mid-project.
For many distributors, Business Central with a well-configured connector fits today. F&SCM is there when the operation outgrows it.
The return shows up in numbers you already track. In Deloitte Digital's 2026 B2B commerce research, suppliers that had fully integrated ecommerce and ERP beat their annual sales goals by about 6.3%, nearly double the margin of less-integrated peers. The same research found that 87% of suppliers are upgrading or planning to upgrade their ERP.
You don't need a heavy custom build to get there. Start with the standard connector and APIs, set the stock rules your team can own, and customize only where the business truly needs it.
Western Computer has spent nearly 40 years and more than 1,750 implementations helping distributors get one version of the truth from the warehouse to every channel. If you want to see where your old ERP is costing you, download our whitepaper, Your Warehouse Is Paying for Your Old ERP.