Amazon Global FBA vs FBM Integration Guide

On Amazon Global, FBA (Fulfillment by Amazon) means you send inventory into Amazon's warehouses and Amazon picks, packs, ships and accepts returns. FBM (Fulfillment by Merchant) means the stock stays in your own warehouse and you ship every order yourself. From an integration point of view the difference is simple: with FBA the stock sits at Amazon and your system has to read it; with FBM the stock sits with you and your system has to write it to Amazon. If you run both models under one seller account, the real job is to manage the two flows from one place without letting them contaminate each other. This guide walks through orders, inventory and invoicing for both.

FBA and FBM: two stock pools, two flows

Most sellers log into one Seller Central account but actually run two different operations. On the FBA side your products are physically at Amazon. When a customer orders, Amazon packs, ships and handles the return. Your job is to plan replenishment shipments on time and to read the warehouse quantity correctly.

On the FBM side the classic marketplace flow applies. An order comes in, you pick it from your own shelves, print the label and, if you are shipping across a border, prepare the customs paperwork. It looks a lot like selling on any domestic marketplace; the difference is international shipping and settlement in a foreign currency.

In both models the sale is booked under your company and lands in your accounts. So the integration must carry both order types into your ERP, but it must treat stock movement differently: an FBA order does not deduct from your own warehouse, an FBM order does. Sellers who get this wrong either deduct twice or not at all, and both mistakes surface at month-end reconciliation.

FBA stock: seeing Amazon's warehouse in your own pool

The most common FBA mistake is counting the units at Amazon on the same line as the units in your own warehouse. Two hundred units in an Amazon fulfilment centre are not on your shelf; if you expose them to eBay or your own webshop you will sell them and be unable to ship.

The right setup treats FBA as a separate warehouse. The integration reads the sellable quantity from Amazon's inventory report on a regular schedule and links that number only to your FBA offer. Your physical warehouse feeds every other channel. In one panel you see two lines: how many units are at Amazon, how many are at home.

The second benefit is replenishment planning. If Amazon's quantity is tracked alongside daily sales velocity, you can see when the next inbound shipment needs to leave. The logic in critical stock and days-of-cover works the same way; the only difference is that the warehouse belongs to Amazon. Inbound rules and storage fees change over time, so keep an eye on the current terms in Seller Central.

FBM orders: shipping from your own warehouse across borders

When an FBM order drops, the clock starts. Amazon tracks the handling time you committed to and late shipments count against account health. The single most important thing in FBM is that the order reaches the warehouse the moment it is placed.

The integration pulls the order, matches items by SKU and barcode, normalises the customer and delivery address, and writes the order to the ERP. For cross-border shipments it also prepares the export paperwork, currency amount and customs data at order time, so the paperwork is ready before the parcel is sealed. If you ship from Türkiye, the micro-export order flow covers the details.

FBM quantity is fed from your single stock pool. When a unit sells on Etsy, the FBM offer on Amazon drops by one; when it sells on Amazon, Etsy drops by one. That is how overselling is prevented. Amazon limits how often offers can be updated, and an integration that respects those limits gets stock changes through without being throttled.

Listing the same product as FBA and FBM

Amazon allows two offers for one product: one fulfilled by Amazon, one by you. This keeps the listing alive when FBA stock runs out; the FBM offer takes over and you ship from home until the next inbound arrives.

On the integration side you track the two offers separately. The FBA quantity is read from Amazon; the FBM quantity is written from your pool. Pricing can differ too, and it usually should, because you carry the shipping cost on FBM. When the price matrix is held as channel × list/sale/floor price, the two offers appear as two rows and you never accidentally push the FBM price onto the FBA offer.

This is where an ownership flag earns its keep. For every product × channel pair there is a clear answer to "does the integration manage this offer, or does Amazon's own tooling?" Mark the FBA stock row as Amazon-managed and the panel will never write to it, which removes the risk of overwriting the fulfilment-centre quantity.

Multiple Amazon marketplaces: sizes, currencies, languages

Amazon Global is not one marketplace. The US, Canada, the European stores, the UAE and others are separate marketplaces with their own currency, language and tax rules. If you sell apparel, size charts differ as well: a European M does not map cleanly to a US M.

A good integration handles these conversions at order time. For US orders the size is shifted one step up according to the product's own size list; content is published in the marketplace language; the order amount is written to the ERP in both the marketplace currency and your home currency. See multi-currency and exchange-rate handling for settlement and international size and measurement conversion for apparel.

Then there is the silence problem. When one marketplace connection breaks, it can take days to notice that orders stopped arriving. Channel monitoring polls every marketplace separately continuously; a marketplace that goes quiet raises an alert and a push notification lands on your phone.

Checklist before you connect

Before wiring Amazon Global into an integration, work through this order:

1. Settle the account and marketplaces. Which countries will you sell in, and which of them with FBA? Approval and tax registration run separately per marketplace.
2. Map SKUs and barcodes. Every Amazon offer must match exactly one product in your catalog. The FBA and FBM offers of the same product share a SKU but carry different stock sources.
3. Define FBA as its own warehouse. Amazon's quantity must never merge with your own.
4. Run shadow mode. For one to two weeks the system only reads and never writes. Use that window to confirm orders and inventory reports are being read correctly.
5. Hand over write access channel by channel. Enable FBM stock writes first, then pricing. The FBA row stays read-only.
6. Test invoicing and paperwork. On the first live order, check the ERP record, the currency amount and the export documents together.

The general sequence is described in integration setup in 4 steps.

How it works with Bulutegra

Bulutegra connects to Amazon's Türkiye and global marketplaces from the same Integration Panel. FBA quantity is read from Amazon and shown on its own line; FBM quantity is fed from the single stock pool and updated together with the other marketplaces. Each order is written to your ERP (Nebim V3, Logo, Mikro, SAP) with customer, line items, currency amount and payment details; invoicing and dispatch continue in your own system. For US orders, size conversion and export paperwork are prepared the moment the order lands. Setup starts in shadow mode, and because the software was first used in the founding company's own multichannel retail operation, the FBA/FBM split was shaped by problems met on the floor. The full channel list is in the Channels section.

If you want to set up FBA and FBM together for Amazon Global, request a demo.