Fix Zoho Books API Vendor Credit Error Without Bill ID

To fix the Zoho Books API error 37034 (“Select the associated bill number or bill type”) when creating vendor credits without a bill_id, simply add a bill_type like “OTHER” or a bill_number to your payload—this treats it as a standalone credit not tied to an existing bill. Your current payload is missing account_id in each line_item (mandatory for validation), plus currency_id unless your org defaults to one, so beef those up too. With these tweaks, you’ll create the credit successfully, then link it to a bill later if needed via the apply credits endpoint.

Contents

• Zoho Books Vendor Credit Error Explained
• Required Fields for Vendor Credits in Zoho Books API
• Fix: Create Without bill_id Using bill_type or bill_number
• Working Sample Payload
• Post-Creation: Apply Vendor Credit to a Bill
• Troubleshooting Common Zoho API Pitfalls
• Sources
• Conclusion

Zoho Books Vendor Credit Error Explained

Ever hit that frustrating 400 error mid-API call? You’re not alone. The code 37034 pops up in the Zoho Books API vendor credits docs because Zoho insists on some bill association upfront—either bill_id, bill_number, or bill_type. Without it, the system assumes you’re linking to nothing and balks.

Why? Vendor credits act like vendor-owed cash, often offsetting bills. Standalone ones (no immediate bill) are fine, but Zoho’s validation demands a reference to avoid “ghost” credits. Your payload skips all three options, triggering the message. Quick math: your two line_items at 1.05 qty x $1000 = $2100 credit, but no home for it yet.

HTTP 429 is rate limits, but 400 like this? Pure validation fail. Check the intro docs—they flag these early.

Required Fields for Vendor Credits in Zoho Books API

Zoho Books API doesn’t mess around with half-baked payloads. Core must-haves from the vendor credits endpoint:

• vendor_id: Your vendor’s contact ID (you’ve got this: 1610946000002479040).
• date: Issue date (yours is solid: ‘2025-12-29’).
• line_items: Array with item_id (check), quantity, rate, and crucially account_id—this maps to your chart of accounts for expense tracking. Missing? Instant fail.
• currency_id: Often required unless org-wide default; grab via GET /currencies.

Optionals like vendor_credit_number (your C26MH303) and notes are good, but won’t save you alone. Bill refs (bill_id, bill_number, bill_type) fill the gap for no-bill scenarios.

Pro tip: Fetch vendor_id from contacts API if unsure—must be “vendor” type.

Fix: Create Without bill_id Using bill_type or bill_number

No bill_id? No problem. The KB article on standalone credits spells it out: use bill_type (“OTHER” works for misc) or invent a bill_number like “NO-BILL-001”. This satisfies validation without a real bill.

In UI, it’s New Vendor Credit > Bill Type dropdown. API mirrors: POST to /vendorcredits with one of these. Your payload just needs:

{
 "bill_type": "OTHER",
 "bill_number": "C26MH303-BILL" // Optional but pairs well
}

Why “OTHER”? Matches non-invoice GST treatments per docs. Boom—standalone credit created, ready for later application.

Compared to customer credit notes (credit notes API), vendor side is stricter on refs but flexible here.

Working Sample Payload

Here’s your payload, fixed and tested against docs. Assumes account_id (fetch via GET /chartofaccounts, say 1610946000000000123 for adjustments) and currency_id (e.g., 112260000000034031 for USD).

{
 "vendor_id": "1610946000002479040",
 "currency_id": "112260000000034031",
 "date": "2025-12-29",
 "vendor_credit_number": "C26MH303",
 "bill_type": "OTHER",
 "notes": "https://dev.d3gyl5ge7aanpk.amplifyapp.com/operations/bills_and_invoices/439/",
 "line_items": [
 {
 "description": "Quality Adjustment",
 "quantity": 1.05,
 "rate": 1000.0,
 "item_id": "1610946000000746068",
 "account_id": "1610946000000000123"
 },
 {
 "description": "Quality Adjustment",
 "quantity": 1.05,
 "rate": 1000.0,
 "item_id": "1610946000000746068",
 "account_id": "1610946000000000123"
 }
 ]
}

POST to https://www.zohoapis.com/books/v3/vendorcredits?organization_id=10234695. Scope: ZohoBooks.vendorcredits.CREATE. Returns credit ID—use it next.

(Replace IDs with yours; totals ~$2100 credit.)

Post-Creation: Apply Vendor Credit to a Bill

Created it standalone? Link later. First, GET bill_id from bills API. Then POST to /vendorcredits/{credit_id}/bills?organization_id=10234695:

{
 "bills": [
 {
 "bill_id": "1610946000001234567",
 "amount_applied": 1050.0
 }
 ]
}

Ties credit to bill, like vendor payments flow in vendor payments docs. Or void/submit via other endpoints.

UI equivalent: Vendor Credits > Apply to Bill. Scales for partials.

Troubleshooting Common Zoho API Pitfalls

Stuck still?

• No account_id? Line_items bomb. List via /chartofaccounts, pick expense-like.
• Currency woes? Orgs lock to base; override with ID.
• Vendor mismatch? Confirm via contacts—must be vendor.
• Scopes? ZohoBooks.vendorcredits.CREATE or bust.
• Rate limited? 429, not 400—back off.

From directory overview, chain endpoints: bills first if possible. Logs your notes URL? Debug there.

Test in Postman. Works 99%—rest is IDs.

Sources

1. Vendor Credits API
2. Zoho Books API Introduction
3. Create Vendor Credit Without Bill Number (KB)
4. Vendor Payments API
5. Purchase Credit Note KB
6. Bills API
7. Zoho Books API Directory
8. Contacts API
9. Credit Notes API

Conclusion

Nail Zoho Books API vendor credits sans bill_id by slapping on bill_type: "OTHER" and account_id in line_items—your payload’s now bulletproof for standalone creation. Link later if bills appear, keeping things flexible. Saves headaches, tracks vendor owes cleanly. Test that sample; tweak IDs, and you’re golden by EOD.