Key Validation Rules

Core validation rules enforced by the API

Validation Rules

Rule	Detail
Organisation & Customer Identity	tin and email are mandatory for both accounting_supplier_party and accounting_customer_party
Tax Consistency	tax_total values must align with the sum of invoice_line tax calculations
Monetary Consistency	legal_monetary_total must be mathematically correct: tax_inclusive_amount = tax_exclusive_amount + total tax
Payment Means Code	payment_means must be a value from GET /resources/payment-means
Telephone Format	telephone must include the international country code and begin with '+' (e.g. +2348...)
Array Minimums	invoice_line requires at least one entry. All other arrays (billing_reference, payment_means, etc.) are optional but must contain at least one entry if the field is included
Currency Code	currency_code must be a valid ISO 4217 code from GET /resources/currencies
Invoice Type Code	invoice_type_code must be a valid code from GET /resources/invoice-types