Amazon inventory integration for Business Central: Which stock is Amazon actually allowed to sell?

Sending stock status from Business Central to Amazon sounds simple.

Business Central says 100.

Amazon gets 100.

Done.

In practice it is rarely that simple.

Because does “100 in stock” actually mean that Amazon is allowed to sell 100?

Maybe 20 are already reserved. Maybe you want to hold back 10 units for other sales channels. Maybe 40 are in a location that cannot be used for Amazon orders.

The most important question in an Amazon inventory integration is therefore not how you send a quantity.

It is how the correct quantity is calculated.

Physical stock and available stock are not the same thing

Imagine this situation:

Physical stock: 100
Reserved for existing orders: 25
Safety stock: 10

Then Amazon should perhaps only get 65.

If the company also has several stock locations, the calculation can become even more complex.

That is why it is important to define a clear inventory rule before the integration is built.

Which system owns the stock?

For some companies, Business Central is the natural inventory master system.

For others it is the WMS.

If the company’s WMS has the most accurate picture of goods, reservations and picking, it may be necessary to use inventory data from there.

Connectify already works with supply chain and WMS-related integrations, where the purpose is, among other things, to automate stock movements and order fulfilment. Connectify

The key point is to avoid two systems that both believe they determine the truth.

Inventory with FBM

With FBM, the company handles fulfilment itself.

That makes stock status critical.

Amazon itself describes inventory and order synchronisation as part of the FBM tools. Sell on Amazon

If Amazon continues to show five units after the last five have been sold through another channel, the company risks receiving an order it cannot fulfill.

That is precisely the situation inventory integration is meant to reduce.

Read also [Amazon FBM integration for Business Central](/en/amazon-fbm-integration-business-central/).

Inventory with FBA

With FBA, part of the stock is physically located at Amazon.

That is why the company has to be able to distinguish between, for example:

• own warehouse
• goods on their way to Amazon
• goods received by Amazon
• FBA stock
• goods reserved or unavailable

That requires different inventory logic than FBM.

We go deeper into this in [Amazon FBA inventory in Business Central](/en/amazon-fba-inventory-business-central/).

Several sales channels make the problem bigger

Imagine that the same SKU is sold via Amazon and your own webshop.

Both channels show 10 in stock.

A customer buys eight in the webshop.

If Amazon is not updated until several hours later, another customer can manage to buy five there.

Now the company has sold 13 items but only had 10.

That is not necessarily Amazon’s or the webshop’s fault.

It is a question of inventory architecture.

How often should inventory be updated?

There is no single right answer.

Some companies can work with periodic updates. Others need more frequent synchronisation.

That depends on, among other things:

• order volume
• stock levels
• the number of sales channels
• the turnover rate of the products
• the risk of overselling

Amazon has both APIs and reports that can be used for inventory-related processes, including inventory reports and listing data with price and stock. Amazon Developer Docs

A good Amazon inventory flow starts with business rules

Before the technical integration is built, the company should be able to answer:

Which warehouses is Amazon allowed to sell from?

Should Amazon have access to the entire available stock?

Should there be safety stock?

How are reservations handled?

What happens if inventory data between the WMS and Business Central disagree?

Only when these questions have been answered does it make sense to build the integration.

The most important takeaway

An Amazon inventory integration is not about sending a number from system A to system B.

It is about making sure Amazon gets the right number.

That can be the difference between a well-functioning multichannel business and a warehouse team that constantly has to explain why goods that do not exist have been sold.

Get your inventory flow between Amazon and Business Central assessed

Relevant internal links: 👉 Business Central integration 👉 Supply Chain integration 👉 Integration platform