Amazon ERP Integration: Order, Inventory and Settlement Sync Explained

For a growing Amazon seller, the gap between Seller Central and the ERP is where time and margin disappear. This guide covers all three integration flows end to end, with the most attention on settlement reconciliation, the layer most projects leave until last.

What Is Amazon ERP Integration?

Every modern Amazon integration runs on the Selling Partner API (SP-API), Amazon’s REST-based API for sellers. Its predecessor, Amazon Marketplace Web Service (MWS), was retired on March 31, 2024. SP-API itself keeps evolving: Amazon has deprecated Orders API v0 in favour of version v2026-01-01, so ask any integration provider which API versions their connector runs on today.

The three data flows

Each flow fails in its own way. Treating them as one project is the most common scoping mistake.

Order Sync: From Amazon to Your ERP

How order import works

The integration polls the SP-API Orders API on a schedule, or reacts to order notifications, and creates a matching sales document in the ERP. The mapping covers:

• Item matching: Seller SKU maps to the ERP item code. Unmapped SKUs should stop the order and raise an alert.
• Customer mapping: Most sellers post orders to one default “Amazon” customer per marketplace.
• Financial fields: Item price, shipping, taxes and promotional discounts each map to their own ERP fields.
• Order ID: Store the Amazon order ID on the ERP document. It links orders to settlement lines later.

A note on buyer data: buyer names and addresses are restricted personal data. Access requires approved roles and a Restricted Data Token, and Amazon’s Data Protection Policy limits how long you may keep them. Store only what fulfilment and tax require, and check retention rules and GDPR or local privacy law before designing your data model.

FBA vs. FBM: different ERP records

Fulfillment by Amazon (FBA): Amazon picks, packs and ships. Most ERPs record these orders as an invoice or cash sale once Amazon reports them shipped, relieving stock from a dedicated FBA warehouse.

Merchant fulfilled (FBM, called MFN in Amazon’s APIs): Your warehouse ships. The integration creates a sales order, your team fulfils it, and the integration sends shipment confirmation and tracking back to Amazon.

Order acknowledgement vs. shipment confirmation

• Order acknowledgement uses the POST_ORDER_ACKNOWLEDGEMENT_DATA feed, which “acknowledges or cancels an order.” Use it when your process needs to formally accept orders or cancel lines you cannot fill. Amazon’s feed documentation does not present it as mandatory for standard Seller Central orders.
• Shipment confirmation uses the order fulfillment feed (POST_ORDER_FULFILLMENT_DATA) or the Orders API. Per Amazon’s order feed documentation, it tells Amazon to charge the buyer, credit your seller account and notify the buyer the order is on the way. Shipment confirmation is the critical return path. Confirm after the expected ship date and the order counts against your late shipment rate.

Inventory Sync: Keeping Stock Accurate Across Channels

FBM inventory: the ERP is the source of truth

For merchant-fulfilled SKUs, the integration reads available quantity from the ERP, applies channel rules and updates the Amazon listing. Use the Listings Items API or the JSON_LISTINGS_FEED. Amazon deprecated the legacy XML and flat-file listings feeds, including POST_INVENTORY_AVAILABILITY_DATA, so any connector still built on them needs replacing.

Rules worth configuring:

• Safety stock: hold back a buffer per SKU so sync delays during peaks do not cause overselling.
• Channel allocation: reserve a share of stock for Amazon when inventory also serves other channels.
• Sync frequency by velocity: near real time for fast movers, batches for slow lines.

FBA inventory: Amazon holds it, you track it

For FBA, the integration’s job is visibility: pull FBA inventory data through SP-API into the ERP or a scheduled report. Amazon reports FBA stock in states such as fulfillable, inbound (working, shipped, receiving), reserved, unfulfillable and researching. Mirroring these states in a dedicated ERP warehouse lets planners reorder against real availability, not a stale total.

A SKU is either Amazon-fulfilled or merchant-fulfilled. If you want to run both models for one product, create separate SKUs instead of pushing merchant quantities onto an FBA listing.

Settlement Reconciliation: The Most Overlooked Part of Amazon ERP Integration

Amazon does not pay you per order. It collects activity over a settlement period of roughly 14 days, deducts its fees and charges, holds some funds in reserve, and disburses one net amount. If the ERP only sees that deposit, your P&L cannot show channel revenue, fee cost or true margin.

Where settlement data comes from

Settlement reports come from the Reports API, not the Finances API. According to Amazon’s settlement report documentation, settlement reports “cannot be requested or scheduled”. Amazon generates them automatically, and your integration finds them with the getReports operation. The current format is GET_V2_SETTLEMENT_REPORT_DATA_FLAT_FILE_V2.

The Finances API serves a different purpose: it exposes financial events as they happen. Mature integrations use both. They post fees and refunds daily from financial events, then use the settlement report as the closing record for each period.

What a settlement contains

• Product sales and shipping credits
• Referral fees: 15% for most categories, with category rates ranging from 5% to 45%
• FBA fulfillment fees: per unit, by size and weight tier, plus Amazon’s 3.5% fuel surcharge on FBA fees from April 17, 2026
• Storage fees: monthly, plus aged inventory surcharges, which under Amazon’s 2026 fee changes start at 181 days
• Advertising charges, when deducted from your seller balance
• Refunds, refund administration fees and promotional rebates
• Reimbursements for lost or damaged FBA inventory
• Reserve movements: funds held under Amazon’s standard reserve period of seven days after delivery (DD+7), and releases of earlier holds

Fee rates change often, so check them against Amazon’s current fee schedule before building GL rules.

A worked example

Here is an illustrative settlement for one 14-day period:

The matching ERP journal entry posts each line to its own account:

When the deposit lands, debit the bank and credit the Amazon clearing account. That account should return to zero for each settlement. Any balance left over is a reconciliation exception.

Two practical notes:

1. Avoid double counting. If order sync already posts invoices against the Amazon customer, the settlement should clear those receivables, not book revenue a second time.
2. Agree the accounting policy first. Some firms book reimbursements as other income, others offset them against inventory shrink or cost of goods sold. Confirm the treatment with your accountant before automating it.

Why spreadsheets break down

Settlement periods do not line up with calendar months. Refunds land a settlement after the sale, storage and advertising run on their own cycles, and reserves shift cash between periods. Under accrual accounting, each needs cut-off handling. At hundreds of orders per period, spreadsheet exceptions pile up faster than anyone can clear them.

The Settlement Reconciliation Sequence: Step by Step

Before you start: confirm the integration has authorized access to financial reports for every seller account and marketplace, and agree a GL mapping for every transaction type. Each marketplace and currency produces its own settlement, so reconcile them separately.

How APPSeCONNECT Supports Amazon ERP Integration

APPSeCONNECT’s Amazon integration connects to Amazon through the official SP-API. It links Seller Central with SAP Business One, SAP S/4HANA, SAP ECC, Microsoft Dynamics 365 Business Central, Dynamics 365 Finance and Operations, NetSuite, Sage 300 and other ERPs. One integration instance can cover several Amazon marketplaces, including the US, UK, Germany, Australia and the UAE.

The platform imports Amazon settlement data covering fees, commissions, advertising costs and refunds, and includes built-in retry, resync and failure alerting. SAP Business One teams running both models can see how order, inventory and payment flows differ in our Amazon FBA and FBM with SAP Business One guide, including daily FBA inventory reports delivered to an FTP or SFTP folder.

Where appse ai Fits: AI Workflows on Top of Amazon Data

Integration moves the data. The next step is acting on it. appse ai is the ERP-first AI workflow automation platform from APPSeCONNECT, built on more than a decade of mid-market ERP integration work and listing Amazon among its supported marketplaces. For Amazon sellers it fits in three places:

• Exception handling: AutoDetect self-healing automation finds anomalies, attempts a fix, and routes persistent problems to a person with context attached. The AI Exception Management Agent detects, routes and resolves operational exceptions like these. That is the work that eats most reconciliation time: unmapped fee types, unmatched orders and clearing balances that will not zero.
• Inventory decisions: the AI Inventory Intelligence Agent monitors stock, supports replenishment and forecasts demand. It helps you plan FBA restocks against aged inventory surcharges and low-stock fees.
• Building the workflow itself: with the Autonomous Workflow Builder, a finance or operations lead describes a process in plain English, for example “when a new settlement report arrives, classify every line, post the journal and alert finance about anything unmapped,” and the platform builds the running workflow. Every AI decision is recorded in an audit log, so finance keeps a full trail of what was posted and why. appse ai runs in the cloud, on-premise, in a private cloud or as a hybrid, so it fits your data residency requirements.

Bringing It Together

The three flows depend on each other. A missed order becomes an inventory error, then an oversell, then a refund in the next settlement that manual reconciliation is likely to misclassify. Automate all three against current SP-API standards and your Amazon channel can grow without your month-end close growing with it.

Frequently Asked Questions