Sage Intacct API Guide (SOAP/XML vs REST)
Sage Intacct offers two APIs: the long-established SOAP/XML API and the modern REST API, which became fully GA in 2025. Both provide access to core accounting features such as journal entries, invoices, bills, payments, and ledgers and Apideck makes them accessible in a streamlined, consistent way.
SOAP/XML API (Fully Supported in Apideck Unify)
The SOAP API is stable, widely adopted, and still used across many integrations.
Uses XML and credential-based authentication
Returns HTTP 200 even when business errors occur
Supports all major accounting operations
Journal entry statuses include: Draft, Posted, Approved, Partially Approved, Reversed, Declined, and a generic “Submitted/Other” state
Ideal when using Apideck Unify, because Apideck abstracts away XML and standardizes objects into a unified format
REST API (Modern & Actively Developed)
The REST API is Sage Intacct’s recommended direction moving forward.
Uses JSON, OAuth 2.0, and standard HTTP codes
Receives ongoing feature updates
Supports the same core accounting objects as SOAP
Adds more accurate workflow fields for journal entries, including:
Draft, Submitted, Pending Approval, Approved, Posted, Rejected, VoidedBetter consistency across errors, metadata, and lifecycle states
Apideck currently supports the REST API as an auth-only connector.
This means Apideck handles OAuth, and you call Sage Intacct REST endpoints through the Apideck Proxy API:
🔗 https://developers.apideck.com/apis/proxy/reference
This gives you full access to the REST API while Apideck handles authentication and connection management. You receive the raw response from Sage Intacct’s REST API and are responsible for your own request and response mapping.
Area | SOAP/XML | REST |
|---|---|---|
Core Accounting Objects | ✔️ Supported | ✔️ Supported |
Journal Entry Workflows | Limited explicit states | More granular & accurate |
Error Handling | XML, embedded errors | JSON, structured codes |
Authentication | Sender & user credentials | OAuth 2.0 (modern standard) |
New Features | No new additions | Actively enhanced |
Both APIs provide the same functional coverage for invoicing, bills, payments, credit notes, and ledgers. The major differences relate to workflow visibility, error patterns, and authentication model.
Which One Should You Use?
Use SOAP (via Apideck Unify) if you want a fully unified accounting layer with normalized objects - no XML and no API complexity.
Use REST (via Apideck + Proxy) if you need approval workflow statuses or access to the newest Sage Intacct API features.