Sage 50 and AvidXchange integration

What moves between them

Vendor master records and approved purchase invoices move from Sage 50 into AvidXchange, since a vendor must exist in AvidXchange before its bills can be coded and paid. GL accounts flow the same direction as a coding reference. After AvidPay settles each invoice, the payment detail, the check number, ACH trace, or virtual-card reference, moves back from AvidXchange into Sage 50 and is written as a vendor payment applied to the matching bill. Approval routing stays inside AvidXchange, so only the resulting approved or paid status crosses back. The cadence is a scheduled poll on both sides, typically every fifteen to thirty minutes, because neither system pushes events.

How ml-connector handles it

ml-connector runs the Sage 50 local agent in a Windows session on the customer machine and stores both credential sets encrypted: the Sage user name and password for the SDK, and the AvidXchange Company and User Tokens for AvidConnect. It reads Sage 50 vendors, bills, and GL accounts through the SDK, pushes them to AvidXchange, then polls AvidXchange for settled payments and writes each one back into Sage 50 as a vendor payment. Sage vendor IDs map to AvidXchange vendor records and Sage GL account codes map to AvidXchange GL codes, so coding lands on valid accounts. Real gotchas are handled: vendors are synced before invoices to avoid payment failures, the agent must not collide with an interactive Sage login because only one SDK session can open a company file, the SDK version must match the installed Sage 50 year, and because Sage has no idempotency key the connector checks for an existing record by reference before writing a payment so a retried poll does not double-post. Failed calls are retried with backoff, and every record carries a full audit trail and can be replayed.

A real-world example

A regional construction and property-services firm of about 120 staff runs Sage 50 on an office server and processes several hundred subcontractor and supplier bills a month. AP staff were keying every invoice into Sage 50, cutting paper checks by hand, and chasing approvals over email, which made month-end slow and left no clear record of who approved what. With Sage 50 and AvidXchange connected, vendors and open bills flow into AvidXchange for digital coding and approval routing, AvidPay issues each payment as a check, ACH, or virtual card, and the settled payment posts back into Sage 50 against the right bill. The team stops re-keying and hand-cutting checks, and the ledger stays current without manual reconciliation.

What you can do

• •Push Sage 50 vendor records into AvidXchange so payments route to the correct payees.
• •Send approved Sage 50 purchase invoices into AvidXchange for coding, approval, and payment.
• •Read settled check, ACH, and virtual-card payments back into Sage 50 as applied vendor payments.
• •Map Sage 50 GL account codes to AvidXchange GL codes so invoices code to valid accounts.
• •Bridge the Sage 50 desktop SDK login and the AvidXchange tokens, with retries and a full audit trail.

Questions

How does ml-connector reach Sage 50 when it has no cloud API?

Sage 50 is desktop software with no REST API, so ml-connector runs a small Windows agent next to the installation that uses the Sage 50 SDK. The agent signs in with a dedicated Sage user name and password and reads or writes vendors, bills, and payments directly against the company data files. The customer machine must stay on and logged in for syncs to run, since the SDK needs an interactive Windows session.

Which direction do payments and invoices move between Sage 50 and AvidXchange?

Vendors and approved purchase invoices move from Sage 50 into AvidXchange, because a vendor must exist there before its bills can be coded and paid. After AvidPay settles a bill, the payment detail moves back from AvidXchange into Sage 50 and is recorded as a vendor payment. Approval routing stays inside AvidXchange, so only the final approved or paid status crosses back.

How does the integration sync if neither Sage 50 nor AvidXchange has webhooks?

Neither system pushes events, so ml-connector polls on a schedule you set, usually every fifteen to thirty minutes. It detects changed Sage 50 records by comparing against the last-sync timestamp and checks AvidXchange for newly settled payments and invoice status. Because Sage 50 has no idempotency key, the connector checks for an existing record by reference before writing, so a repeated poll never double-posts a payment.