# RegCheck API — Overview & Authentication

> RegCheck is a SOAP-based ASP.NET ASMX web service for vehicle registration lookups across 50+ countries, operated by Infinite Loop Development Ltd, Ballyliffin, Co. Donegal, Ireland.

## API Endpoint

- **Endpoint:** `https://www.regcheck.org.uk/api/reg.asmx`
- **WSDL:** `https://www.regcheck.org.uk/api/reg.asmx?wsdl`

The service is SOAP/ASMX. Each country has its own operation name (e.g. `/Check` for UK, `/CheckFrance` for France). The XML response contains a `vehicleJson` element with vehicle data encoded as JSON, making it easy to consume from JavaScript clients.

## Authentication

A **username** is required to call the API. A username and password are needed to access the account dashboard. Test accounts with 10 free credits are available after email verification at [www.regcheck.org.uk](https://www.regcheck.org.uk).

## Credit System

- Each successful lookup consumes one credit.
- When balance reaches zero, no further requests can be made.
- Credits can be purchased via PayPal from the account dashboard.
- A **low balance warning** email threshold can be configured in the dashboard.
- A **daily credit limit** can be requested to cap usage per day.
- Credit balance can be checked programmatically:
  ```
  https://www.regcheck.org.uk/ajax/getcredits.aspx?username=YOUR_USERNAME
  ```
  A zero or negative value means the account is out of credits.

## IP Locking

By default, API access is permitted from any IP address. For additional security, access can be locked to a specific set of IP addresses — contact support to request this.

## Test Plates

Every supported country has a free test registration number that can be queried without consuming credits. These are listed in each country's documentation page and are useful during development and integration testing.

## Offline vs. Live Data

Some countries hold complete vehicle datasets on RegCheck's own servers (offline data). These tend to return richer data faster. Countries with offline data include:

- United Kingdom
- Denmark
- Finland
- Norway
- Sweden
- Ukraine
- Israel

Other countries query live government or third-party data sources in real time.

## Response Format

All responses are XML. The key field is `vehicleJson`, which contains a JSON-encoded object with standardised top-level fields, extended with country-specific data where available.

Common top-level JSON fields across most countries:

| Field | Description |
|---|---|
| `Description` | Human-readable vehicle description |
| `RegistrationYear` | Year of first registration |
| `CarMake.CurrentTextValue` | Make |
| `CarModel.CurrentTextValue` | Model |
| `MakeDescription` | Make (plain string) |
| `ModelDescription` | Model (plain string) |
| `EngineSize.CurrentTextValue` | Engine displacement (cc unless stated) |
| `FuelType.CurrentTextValue` | Fuel type |
| `VechileIdentificationNumber` | VIN (note: typo in field name is intentional) |
| `ImageUrl` | URL to a representative vehicle image |

Country-specific fields are documented in each country's page.

## Dashboard

Log in at any associated website (e.g. [www.regcheck.org.uk](https://www.regcheck.org.uk)) to access:

- Remaining credit balance
- Usage graph
- PayPal top-up
- Low balance warning configuration
- Daily limit requests