> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cleariflow.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Cleariflow Bank Validation API provides comprehensive validation for International Bank Account Numbers (IBAN) and Business Identifier Codes (BIC) through a modern RESTful JSON interface, supporting 50+ countries with detailed validation and formatting information.

## Getting started

<Card title="IBAN validation" icon="credit-card" href="bank-validation/iban">
  The `iban` endpoint validates International Bank Account Numbers with comprehensive country-specific validation, format checking, and detailed structural information for financial applications.
</Card>

<Card title="BIC validation" icon="building" href="bank-validation/bic">
  The `bic` endpoint validates Business Identifier Codes, providing detailed breakdown of bank codes, country information, and institution types for international banking operations.
</Card>

<Card title="Supported countries" icon="globe" href="bank-validation/countries">
  Comprehensive list of supported countries for IBAN and BIC validation, including country codes, currency information, and specific formatting requirements.
</Card>

### REST Architecture

The Bank Validation API follows REST principles, utilizing predictable resource-oriented URLs and standard HTTP status codes for seamless integration and error handling.

### HTTPS Security

All API communications are secured using TLS 1.2 or higher encryption protocols to ensure data integrity and privacy.

### API Versioning

The Bank Validation API maintains backward compatibility through versioning, currently operating on Version 1 with planned future enhancements.

### Authentication

Your API key serves as the exclusive credential for accessing the Bank Validation API. Each Cleariflow service requires a unique key, ensuring secure and isolated access across different APIs.

## Response and error codes

When requests fail, the API returns structured JSON error responses with specific codes and descriptions for effective troubleshooting.

| Code | Type                  | Details                                                                                                                                                     |
| ---- | --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 200  | OK                    | Everything worked as expected.                                                                                                                              |
| 400  | Bad request           | Bad request - missing or invalid parameters.                                                                                                                |
| 401  | Unauthorized          | The request was unacceptable. Typically due to the API key missing or incorrect.                                                                            |
| 422  | Quota reached         | The request was aborted due to insufficient API credits. (Free plans)                                                                                       |
| 429  | Too many requests     | The request was aborted due to the number of allowed requests per second being reached. This happens on free plans as requests are limited to 1 per second. |
| 500  | Internal server error | The request could not be completed due to an error on the server side.                                                                                      |
| 503  | Service unavailable   | The server was unavailable.                                                                                                                                 |