Zoho Books and Basware integration

What moves between them

Purchase orders and vendor invoices flow bidirectionally between Zoho Books and Basware. Purchase orders created in Zoho Books are synced into Basware's AP workflow for matching and approval. Invoices received in Basware are pushed into Zoho Books for payment processing and general ledger posting. Vendor master data is aligned in both directions so invoices and purchase orders reference valid vendors in both systems. Zoho Books is the source of truth for GL account mapping and multi-currency exchange rates, while Basware handles the invoice matching and approval workflow.

How ml-connector handles it

ml-connector maintains two separate credential sets: OAuth2 user-delegated refresh tokens for Zoho Books (rotated proactively before the 1-hour access token expires) and OAuth2 Client Credentials for Basware's P2P API (cached and refreshed on 401). Every Zoho Books call includes the organization ID query parameter (resolved once per customer on first authentication) and routes to the correct regional base URL determined at token response time. Every Basware Network API call includes a unique X-BW-REQUEST-ID UUID v4 header to ensure idempotency. Zoho Books rate limit (100 requests per minute) is tracked per region and backed off with exponential jitter when 429 is returned. Purchase orders are mapped from Zoho Books line items to Basware purchase requisitions, matching on supplier code. Vendor records are upserted so new vendors in Zoho flow into Basware's vendor master. Invoices received from Basware are posted into Zoho Books' Bills entity with the original invoice number as reference for deduplication. Because Zoho requires explicit organization ID routing and Basware requires regional matching, every customer is provisioned with credentials for exactly one Zoho Books organization and one Basware region.

A real-world example

A mid-sized distributor uses Zoho Books for accounting across three regions (US, EU, India) and Basware for centralized AP automation and e-invoicing. Before the integration, the accounts payable team entered invoices manually in Zoho after Basware approved them, matching invoices to the correct purchase order and general ledger account by hand. This created duplicate data entry, reconciliation lag, and invoice posting errors. With Zoho Books and Basware connected, approved invoices from Basware flow directly into Zoho Bills, matched to the original purchase order and mapped to the correct GL account, while new purchase orders in Zoho automatically appear in Basware's AP workflow the same day. Month-end close is faster because the AP aging report in Zoho agrees with the invoice register in Basware without manual reconciliation.

What you can do

• •Sync purchase orders from Zoho Books into Basware purchase requisitions with line-item detail and supplier codes.
• •Push approved invoices from Basware into Zoho Books Bills, mapped to the correct purchase order and GL account for payment processing.
• •Align vendor master data bidirectionally so new suppliers in Zoho appear in Basware and overrides in Basware do not conflict with API imports.
• •Route all Zoho Books calls through the correct regional base URL per organization and all Basware calls to the matching regional deployment.
• •Handle OAuth2 token refresh for both systems, track rate limits, and retry with backoff on HTTP 429 with a full audit trail.

Questions

Which direction does data move between Zoho Books and Basware?

Bidirectional. Purchase orders flow from Zoho Books into Basware for AP matching and approval. Approved invoices flow from Basware back into Zoho Books for payment processing and posting to the general ledger. Vendor master data is aligned in both directions so suppliers referenced in purchase orders and invoices are valid in both systems.

How does ml-connector handle Zoho Books regional base URLs and organization ID routing?

ml-connector extracts the region from the OAuth2 token response and routes all subsequent calls to the matching regional base URL (US, EU, India, Australia, Japan, Canada, China, or Saudi Arabia). The organization ID is resolved once at setup and passed as a query parameter on every Zoho API call. This ensures multi-region Zoho Books instances are routed correctly without manual region selection.

How are invoices matched between Zoho Books and Basware to prevent duplicates?

ml-connector uses the invoice reference number as the deduplication key when posting invoices from Basware into Zoho Books. Purchase orders are matched by supplier code and line-item totals. A full audit trail tracks every sync event so failed or duplicate posts can be identified and replayed if needed.