SAP Business One and AvidXchange integration

What moves between them

Most data moves from SAP Business One into AvidXchange. The connector reads vendor records from BusinessPartners filtered to suppliers, plus GL accounts from ChartOfAccounts and cost centers from ProfitCenters, and pushes them into AvidXchange so AP staff can code invoices against valid accounts. Purchase invoices flow from SAP Business One into AvidXchange for approval routing and payment, carrying their vendor, line items, GL coding, and any PO reference for matching. Payment data flows the other direction: after AvidXchange executes a check, ACH, or virtual card payment, the settled payment record is pulled back and written into SAP Business One as an OutgoingPayment linked to the original purchase invoice. Vendors and GL accounts are kept in step so coding stays valid. Cadence is scheduled, since neither side offers a reliable public webhook for this pair.

How ml-connector handles it

ml-connector stores both credential sets encrypted. On the SAP Business One side it accepts the full Service Layer base URL per customer, logs in to obtain the B1SESSION cookie, reuses that session across requests rather than re-authenticating each time, and when a call returns error code -5002 it logs in again and replays the request. On the AvidXchange side it passes the Company Token and User Token as headers on every call. Vendor sync runs first and is mandatory, because a missing vendor in AvidXchange causes payment failure; SAP B1 CardCode maps to the AvidXchange vendor key, and ChartOfAccounts codes map to the GL codes AP staff select. Purchase invoices submit as batches, and because the Service Layer has no idempotency keys, the connector deduplicates by DocNum before re-posting on a retry. Payment results pull back on a schedule and post as OutgoingPayments against the matching purchase invoice by DocEntry. Approval routing and payment method stay inside AvidXchange, so the connector reads the resulting status rather than driving the workflow. AvidXchange rate limits and pagination are not publicly documented, so the connector applies conservative backoff. Every record carries a full audit trail and can be replayed if a downstream call fails.

A real-world example

A mid-sized property management firm with around 200 employees runs SAP Business One for its general ledger, vendor master, and purchasing across several buildings, and adopts AvidXchange to automate accounts payable. Before the integration, staff exported vendor lists and GL codes by hand so invoices could be coded in AvidXchange, then re-keyed each paid bill back into SAP Business One as an outgoing payment, which left the ledger a day or two behind and made bank reconciliation slow. With SAP Business One and AvidXchange connected, vendors and GL accounts sync automatically, purchase invoices move over for approval and payment, and every settled check or ACH posts back to SAP Business One against the right purchase invoice. Reconciliation starts with the payments already booked, and the manual re-keying step is gone.

What you can do

• •Push SAP Business One vendors into AvidXchange so invoices route to valid payees before any payment runs.
• •Sync GL accounts and cost centers into AvidXchange so AP staff code invoices against the correct SAP Business One accounts.
• •Send purchase invoices from SAP Business One into AvidXchange for approval routing and payment.
• •Write settled check, ACH, and virtual card payments back into SAP Business One as outgoing payments on the original invoices.
• •Bridge the SAP B1SESSION cookie login and AvidXchange company and user tokens, with retries and a full audit trail on every record.

Questions

Which direction does data move between SAP Business One and AvidXchange?

Vendors, GL accounts, cost centers, and purchase invoices move from SAP Business One into AvidXchange. Settled payment results move the other way, from AvidXchange back into SAP Business One as outgoing payments against the original purchase invoices. Vendor and GL records are kept aligned so invoice coding stays valid.

Why must vendors sync to AvidXchange before invoices?

AvidXchange requires a vendor to exist before an invoice can be coded and paid, and a missing vendor causes a payment failure. ml-connector runs vendor sync first, mapping the SAP Business One supplier code to the AvidXchange vendor, so every invoice it submits already has a valid payee. Payment delivery method is then controlled by the supplier's preference inside the AvidPay Network.

How does the integration handle the SAP Business One session and the lack of webhooks?

ml-connector logs in to the Service Layer to obtain the B1SESSION cookie and reuses it across requests, re-authenticating and replaying the call when SAP returns the -5002 session timeout error. Because AvidXchange has no public webhook support and SAP B1 webhooks require server-side admin setup, the connector polls on a schedule rather than relying on a push, deduplicating purchase invoices by DocNum so a retry never creates a duplicate.