Error Codes
All errors return a consistent JSON structure with an error field describing what went wrong.
Error Response Structure
{ "error": "Insufficient balance. Available: ₦45,000 | Required: ₦50,050" }

HTTP Status Codes

StatusMeaningCommon Causes
400Bad RequestMissing required parameters, invalid values, insufficient balance.
401UnauthorizedMissing or invalid API key, suspended account.
404Not FoundEndpoint URL is incorrect.
409ConflictDuplicate reference — this request was already processed.
500Server ErrorInternal error. Retry after a few seconds. Contact support if persistent.

Common Error Messages

Error MessageResolution
Invalid API keyCheck your key is correct and starts with NDAPI-TEST- or NDAPI-LIVE-
Insufficient balanceTop up your operator balance before initiating the transfer
Duplicate referenceUse a unique reference for each transfer request
amount_ngn, account_number, bank_code, reference requiredAll four fields are mandatory for transfer requests
Operator account suspendedContact ndapi.admin@nolubz.com immediately