Exact Online and Amazon Seller Central integration

What moves between them

Purchase orders and invoices flow bidirectionally. Exact Online purchase orders sync to Seller Central vendor purchase orders on update. Seller Central vendor invoices flow back to Exact Online as purchase invoice lines, mapped to the GL accounts and cost centers defined in Exact Online. Vendor payment and settlement data from Seller Central is polled on a daily or weekly schedule and posted as journal entries into Exact Online's GL for accounting reconciliation. Invoices older than 2 years are not returned by Seller Central API.

How ml-connector handles it

ml-connector maintains both OAuth 2.0 token sets encrypted, refreshing access tokens on 401 responses and rotating Exact Online refresh tokens on each use. Exact Online division ID is fetched and cached at connection time. For outbound flow, when an Exact Online purchase order is updated, ml-connector posts it to Seller Central's vendor purchase order endpoint, mapped to the vendor account in Seller Central. For inbound flow, ml-connector polls Seller Central's Orders API, Finances API, and vendor invoice endpoints daily, hydrating the webhook notifications from Exact Online when they arrive, and posts settlement journal entries into Exact Online's GL with line items allocated to the matching cost centers. Because Seller Central's financial settlement events cannot be pushed, polling is mandatory on that path and is not optional. Rate limiting is handled with exponential backoff. Every record carries transaction timestamps and source references so manual adjustments in Exact Online can exclude already-synced periods.

A real-world example

A European SME manufacturer uses Exact Online for purchasing and accounts payable, and sells finished goods to distributors and retailers via Amazon Seller Central. Before integration, the procurement team managed purchase orders in Exact Online and vendor invoices in Seller Central separately, leading to duplicate invoices and reconciliation delays at month-end. With Exact Online and Seller Central connected, purchase orders and vendor invoices sync automatically, settlement payments from Seller Central flow into Exact Online's payables ledger, and the accounts payable team closes the books without manual matching and re-entry.

What you can do

• •Sync Exact Online purchase orders to Seller Central vendor purchase orders, keeping both systems current on procurement status.
• •Pull vendor invoices from Seller Central back into Exact Online as purchase invoice lines allocated to the correct GL accounts.
• •Poll Seller Central financial settlement and vendor payment events daily and post them into Exact Online's general ledger for automatic accounts payable reconciliation.
• •Bridge OAuth 2.0 tokens on both sides, refresh on expiry, and rotate Exact Online refresh tokens per its 30-day requirement.
• •Handle the asymmetry of Exact Online webhooks and Seller Central's polling-only settlement data with a single unified audit trail.

Questions

Which direction does data move between Exact Online and Amazon Seller Central?

Purchase orders and invoices move bidirectionally. Exact Online purchase orders sync to Seller Central vendor purchase orders. Seller Central vendor invoices and settlement events flow back into Exact Online as purchase invoice lines and GL postings. Because Seller Central does not support push notifications for financial settlements, the settlement data is polled rather than pushed.

Why does ml-connector poll Seller Central if Exact Online supports webhooks?

Exact Online webhooks are supported for purchase orders and invoices, but Seller Central does not offer direct HTTP webhooks; it requires AWS EventBridge or SQS. More importantly, Seller Central's financial settlement events and vendor invoice submission results cannot be delivered via any push mechanism and must be polled via the Finances API and Orders API on a schedule.

How are cost centers and GL accounts mapped between the two systems?

Cost centers and GL accounts are configured once per customer in Exact Online. When vendor invoices flow from Seller Central back into Exact Online, ml-connector maps each line item to the pre-configured GL account and cost center for that vendor, ensuring invoice lines post to the correct accounting dimension. Settlement payments are allocated to a single GL account per payment type configured at setup time.