Sage Intacct and PayPal integration

What moves between them

The main flow is PayPal into Sage Intacct. When a PayPal invoice is sent or a capture completes, ml-connector receives the webhook notification and creates or updates a vendor invoice in Sage Intacct, mapped to the correct GL account and dimension. Payment confirmations from PayPal post GL entries that offset the invoice and record the cash receipt. Because Sage Intacct has no webhook system, reference data such as vendors and GL accounts are kept in sync by periodic polling from Intacct to validate incoming PayPal transactions. The schedule is configurable, typically daily or per-transaction depending on your cash-flow needs.

How ml-connector handles it

ml-connector stores PayPal OAuth credentials and presents the Bearer token on every REST request, refreshing when a 401 response is received. On the Sage Intacct side it maintains a cached session using the senderId, senderPassword, companyId, userId, and userPassword, refreshing the sessionid every 50 minutes before expiry. PayPal webhooks arrive with RSA-SHA256 signatures; ml-connector verifies each against the paypal-transmission-sig header using the webhook certificate from the Developer Dashboard, rejecting unsigned or tampered events. Invoices from PayPal are serialized into Sage Intacct's XML gateway as APBILL records with the correct DIMENSION references so GL posting lands on valid cost centers. Because Sage Intacct's XML gateway requires all operations to serialize through a single POST, ml-connector batches operations to minimize roundtrips and detects application-level errors by parsing XML response bodies for errormessage tags. Every invoice and payment record carries a full audit trail and can be replayed if the GL posting fails.

A real-world example

A mid-sized online retailer uses PayPal to accept customer payments and issue refunds, and Sage Intacct for accounting and general ledger. Before the integration, the finance team manually exported PayPal transaction reports once a day and keyed each invoice and payment receipt into Sage Intacct by hand, then spent the first days of month-end reconciling the PayPal clearing account against the AP aging report. With PayPal and Sage Intacct connected, each PayPal invoice and payment posts automatically to the GL on receipt, the clearing account stays in sync, and month-end reconciliation is complete before the close window opens.

What you can do

• •Receive PayPal invoice and payment notifications via webhook and post them to Sage Intacct as GL entries.
• •Map PayPal transactions to the correct Sage Intacct GL accounts and dimensions so payments land on valid cost centers.
• •Authenticate PayPal with OAuth 2.0 and verify RSA-SHA256 webhook signatures, and Sage Intacct with session-based XML credentials.
• •Validate PayPal invoices against Sage Intacct vendors and GL accounts, rejecting mismatches to prevent GL posting errors.
• •Retry failed GL postings with exponential backoff and preserve a full audit trail on every transaction.

Questions

How does the integration handle PayPal webhook signatures and Sage Intacct session expiry?

PayPal webhooks arrive with RSA-SHA256 signatures verified against the paypal-transmission-sig header. ml-connector checks the signature against your Developer Dashboard webhook certificate before processing any event. On the Sage Intacct side, ml-connector maintains a session keyed on senderId, companyId, and userId, and refreshes the sessionid every 50 minutes before the 50-minute cache timeout occurs, so session expiry never interrupts a GL posting.

Which direction does data flow between PayPal and Sage Intacct?

The main flow is PayPal into Sage Intacct. Invoices, captures, and refunds move from PayPal into Sage Intacct as AP bills and GL entries. Reference data such as vendors and GL accounts are periodically synced from Sage Intacct to validate incoming PayPal transactions. Sage Intacct does not push data back to PayPal, since PayPal has no AP or GL object model.

What happens if a PayPal webhook arrives while a Sage Intacct GL posting is in progress?

ml-connector stores the webhook event and applies exponential backoff when the Intacct session is busy or when an XML gateway operation fails. Because Sage Intacct's XML gateway serializes all operations through a single POST and may return application-level errors in the HTTP 200 response body, ml-connector parses XML responses for errormessage tags and retries. Every transaction carries a unique audit trail and can be manually replayed if a posting fails and needs recovery.