Amazon by Codisto makes it easy to set separate available inventory quantities on Amazon for your products and sync them to the inventory counts in your Shopify catalog.

With Amazon by Codisto, you can apply different inventory rules to products individually or in filtered groups, or maintain one consistent inventory rule across all of your products.

Setting Inventory Rules

Each inventory rule is made up of a combination of some, or all, of the following:

Operator: This is the type of inventory rule that you will use to determine the available inventory count on Amazon and can be chosen from a drop-down list of options.

• Inventory Level: When the "Inventory Level" operator is selected, the available inventory for your Amazon offer will be synced to your current inventory count for that product exactly. Any time an order is made for that product on Amazon, your Shopify store, or any other connected sales channels, your inventory count will be updated on both Amazon and your Shopify store.
• Fixed Quantity: When the "Fixed Quantity" operator is selected for a product, the Amazon inventory for your offer will be fixed to the amount specified in the Input field. The inventory quantity for your Amazon offer will not change even when an order is made from Shopify or Amazon, so we recommend that you don't use fixed quantity for products that are likely to go out of stock, or monitor your stock levels regularly so that you are not receiving orders for out-of-stock products.
• Quantity Buffer: The "Quantity Buffer" operator allows you to reserve stock for your Shopify store by reducing the inventory quantity on your Amazon offer for a product by a specific amount. 

Input: Some operators need to be combined with a numerical input value, for example, for the "Quantity Buffer" operator, the Amazon inventory count will be equal to the Shopify quantity minus the buffer amount you enter in the input field.

Result: In Single Edit and Bulk Edit listing modes, the "Result" is a preview of the current inventory count that will appear on your amazon listing for a product after the above calculations are made.

You can apply inventory rules to products individually, in filtered groups or in bulk across your entire catalog using Bulk Edit Mode, or to individual products using Single Edit Mode.

You can also map to inventory values stored in custom fields in your Shopify catalog, or, if you are using a third-party inventory management tool, or simply want to keep the current inventory values for your products on Amazon without them being synced to your Shopify inventory, you can turn inventory sync off completely. 

Examples of Inventory Rules

The below table shows examples of how combining operators and input values will determine the Amazon inventory (result) based on the Shopify inventory count for that product. For more information on the individual operators and how they work, see below.

Shopify Inventory	Operator	Input	Result
10	Inventory Level	-	10
10	Fixed Quantity	5	5
10	Quantity Buffer	2	8
10	Max Quantity	7	7
10	Max Quantity	15	10

Mapping Inventory to a Custom Field in Shopify

If you have inventory values stored in custom fields in Shopify, you can map those fields using Attribute Mapping.

Simply navigate to the Listings View and select Attribute Mapping, then use the drop-down menu to select the field where the inventory values you wish to use are stored, and save your changes.

Turning Inventory Sync Off

In some cases, you may want to disable Inventory sync completely if you:

1. Are using a third-party inventory management or shipping tool that manages your Amazon inventory sync.
2. Want to keep your current inventory values on Amazon as they are so that any changes to your inventory in Shopify are not synced to your Amazon inventory. Amazon orders will decrease your Amazon inventory quantity, but will not have affect your Shopify inventory counts.
3. Want to manage your Amazon inventory directly from Amazon Seller Central.

Note: If you are selling products through FBA (Fulfilment by Amazon), it is not necessary to turn inventory sync off. FBA orders on products synced by Amazon by Codisto will not change your Shopify inventory counts; Only FBM (Fulfilled by Merchant) orders on products that are synced by Amazon by Codisto will be synced to your Shopify inventory count.

You can turn inventory sync off using Attribute Mapping Mode.

Simply navigate to the Listings View and select Attribute Mapping, then untick the checkbox for "Keep inventory in sync from Shopify to Amazon" in the Amazon Inventory section and save your changes.