Sage Intacct and Avalara integration

What moves between them

Transactions flow from Sage Intacct into Avalara for tax determination. When a bill or sales order is posted in Intacct, ml-connector reads the transaction details, customer, and item codes and posts them to Avalara. Avalara returns the calculated tax amount, rate, and jurisdiction breakdown. ml-connector then posts the tax GL entries back into Intacct's general ledger, allocated to the correct tax accounts for that jurisdiction. Reference data such as customers, companies, and tax codes are aligned in both directions so transactions land on valid tax categories. The sync runs on a schedule you define, typically aligned with your billing cycle, and can also be triggered manually when a high-value transaction posts.

How ml-connector handles it

ml-connector manages two different authentication flows. On the Intacct side, it caches the session token and automatically refreshes it before the 50-minute expiry, re-authenticating with senderId and companyId if the token is stale. On the Avalara side, it encodes the Account ID and License Key as HTTP Basic Auth and presents it on every request. Because both systems are pull-only, ml-connector polls Intacct for posted transactions and Avalara for calculated tax determinations on a scheduler, rather than waiting for either system to push. Intacct's XML gateway requires careful handling: HTTP 200 responses may contain application errors in the XML body, so ml-connector parses for errormessage and status elements rather than treating all 200s as success. Avalara enforces rate limits with HTTP 429, so ml-connector backs off and retries with exponential jitter. Document codes in Avalara act as idempotency keys: reusing a committed transaction code will return a DocumentCodeConflict error, so ml-connector tracks which transactions have been posted to Avalara and does not resubmit them. Invalid addresses cause Avalara tax calculation to fail, so ml-connector pre-validates customer addresses with the /addresses/resolve endpoint before posting. Every record carries a full audit trail and can be replayed if a calculation or GL posting fails.

A real-world example

A mid-sized multi-state software reseller uses Sage Intacct for accounting and billing. Their sales team closes deals in Intacct, but before the integration, the finance team manually reviewed each transaction for tax nexus, looked up the correct tax code for the product, calculated tax by hand or with spreadsheets, and entered the tax GL entries at month-end, often discovering errors during close. With Sage Intacct and Avalara connected, each transaction in Intacct is automatically classified for tax jurisdiction and nexus the moment it posts, Avalara calculates the correct tax amount in real time, and the tax GL entry is posted to Intacct automatically. The finance team no longer re-enters tax data, and month-end close includes accurate tax liability without manual rework.

What you can do

• •Post transactions from Sage Intacct to Avalara and receive calculated tax amounts, rates, and jurisdiction breakdowns in real time.
• •Automatically post tax GL entries from Avalara tax calculations back into Sage Intacct general ledger, allocated to the correct tax accounts.
• •Manage session tokens for Sage Intacct, automatically refreshing before 50-minute expiry, and HTTP Basic Auth credentials for Avalara on every request.
• •Validate customer addresses with Avalara before posting transactions, and use document codes as idempotency keys to prevent duplicate tax calculations.
• •Poll both systems on a schedule you control, back off on Avalara rate limits with retries, and maintain a full audit trail for every transaction and tax determination.

Questions

Which direction does data move between Sage Intacct and Avalara?

Transactions flow from Sage Intacct into Avalara for tax determination. Avalara returns calculated tax amounts, rates, and jurisdiction details. ml-connector then posts the tax GL entries back into Sage Intacct general ledger. Reference data such as customers and tax codes are aligned in both directions so transactions land on valid tax categories.

How does ml-connector handle Sage Intacct's session-based authentication and XML gateway?

ml-connector caches the Intacct session token and automatically refreshes it before the 50-minute expiry. Because the XML gateway delivers HTTP 200 for application-level errors, ml-connector parses the XML response body for errormessage and status elements rather than treating all 200s as success. This prevents silent failures from being treated as successful posts.

What happens if an address is invalid or a transaction code is reused?

ml-connector pre-validates customer addresses with Avalara's /addresses/resolve endpoint before posting transactions, so invalid addresses fail early rather than causing silent tax calculation failures. Document codes in Avalara act as idempotency keys: reusing a committed transaction code returns a DocumentCodeConflict error, so ml-connector tracks posted transactions and does not resubmit them.