Number Plate Recognition API FAQ
Everything you need to know about NPR API: accuracy, ANPR vs ALPR, UK GDPR compliance, integration, and pricing.
A number plate recognition API, also called an ANPR API (Automatic Number Plate Recognition) or ALPR API (Automatic License Plate Recognition), is a web service that reads vehicle registration plates from images. You send an image via a REST API and receive structured JSON containing the plate registration, a confidence score, and processing metadata. It lets you add ANPR capability to any application without specialist cameras, on-site servers, or machine learning expertise.
They are different names for the same technology. ANPR (Automatic Number Plate Recognition) is the standard term in the UK and Europe, while ALPR and LPR (Automatic License Plate Recognition) are used in North America. NPR API performs the same job whichever term you use: reading vehicle registration plates from images and returning machine-readable data.
NPR API achieves 99.8% recognition accuracy on standard-quality images. The engine is trained on millions of diverse plate samples and performs well in challenging conditions including low light, rain, motion blur, high camera angles, and partial occlusion. Every result includes a confidence score, so you can set your own acceptance thresholds for automated workflows.
NPR API is built for UK number plates first, including current and historic formats, and supports registration plates from over 90 countries including EU member states, the US, and Australia. The API automatically detects the region and plate format, including two-line plates and special characters.
Yes. NPR API works with images from any camera: existing CCTV systems, IP cameras, dashcams, or mobile phones. There is no need for dedicated ANPR camera hardware: if your camera can produce a JPEG, PNG, WebP, HEIC or AVIF image where the plate is visible, the API can read it. iPhone and Android photos work as-is, with no conversion needed. This makes it ideal for adding number plate recognition to existing security and car park camera systems.
Integration takes minutes. Sign up for a free account, generate an API key from your dashboard, and make a POST request to the /api/v1/recognise endpoint with your image and your key in the X-API-Key header. The response is clean JSON. Because it is a plain REST API, it works from any language: Python, JavaScript, PHP, C#, Go, or anything else with an HTTP client. Full code examples are in the API documentation.
Yes. By default the API returns the most prominent plate in the image. Set the multiple parameter to true and the API returns every visible plate, each with its own registration, confidence score, and country. This is useful for car park overviews, multi-lane capture, and yard management.
Yes. The batch API accepts large sets of images and processes them asynchronously. Submit a batch, then poll its status or receive a webhook notification the moment results are ready. This is ideal for back-processing archived footage, bulk imports, and high-volume overnight jobs.
Every plan includes a monthly credit allowance, and each recognition request uses credits from it. There is one transparent rate card on every plan, with no contracts and no sales calls. There is a free plan for evaluation and development with no credit card required. See the pricing page for current plans and the credit rate card.
Rate limits depend on your plan, scaling from evaluation-friendly limits on the free tier to high-throughput limits on paid and enterprise plans. If you exceed your rate limit, the API returns a 429 Too Many Requests response with a Retry-After header so your integration can back off gracefully.
Yes, provided it is used lawfully. ANPR is widely used in the UK for parking management, access control, and security. Because number plates are personal data under UK GDPR, you need a lawful basis for processing, appropriate signage where required, and sensible retention policies. The ICO publishes specific guidance on ANPR. NPR API supports compliance with zero-retention image processing and gives you full control over what plate data you store.
Yes. NPR API is fully UK GDPR compliant. Images are processed in memory and immediately discarded. We offer zero-retention processing, and no image data is stored on our servers. You control what happens to recognised plate data in your own systems.
Yes. Enterprise plans include an on-premise deployment option that runs on your own infrastructure or edge devices. This suits applications requiring very low latency, air-gapped environments, or strict data residency requirements. Contact our team to discuss enterprise deployment.
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