ANPR Cameras Explained: A Plain-English Guide for Businesses

Automatic Number Plate Recognition, usually shortened to ANPR, is no longer just something you see on motorway gantries. Business parks, industrial sites, hotels, schools and private car parks across the UK now use it to manage vehicle access and keep track of who comes and goes.

If you are thinking about ANPR for your premises, this plain-English guide explains how it works, what it is typically used for, and what data protection law expects of you as the operator.

What is ANPR?

ANPR is a camera-based system that reads vehicle number plates automatically. The Information Commissioner's Office (ICO) describes it as technology that reads vehicle registration marks from vehicles passing cameras on public or private roads and in car parks, and notes that it can process large volumes of data in real time.

Police forces, government agencies and private operators all use ANPR, but they use it for very different purposes and under different rules.

How does ANPR work?

Although systems vary, the basic process is straightforward:

• Capture: a camera positioned at an entrance, exit or roadway photographs each vehicle as it passes.

• Read: software picks out the number plate in the image and converts the characters into text.

• Record: according to the ICO, a typical system stores an overview image of the vehicle, a close-up of the plate and the registration itself, often with the date, time and location.

• Compare: the registration can then be checked against a list, such as permitted staff vehicles, booked visitors or vehicles you have flagged, and the system acts on the result.

That last step is where ANPR earns its keep. A match can open a barrier, log a visit, start a parking timer or send an alert to whoever is responsible for the site.

Common uses for businesses

For commercial and industrial clients, ANPR tends to be used for a handful of practical jobs:

• Access control: barriers or gates open automatically for authorised vehicles, so staff and regular visitors don't need fobs, cards or intercoms.

• Car park management: monitoring how long vehicles stay, for example where parking is time-limited for customers.

• Site logging: keeping an accurate, time-stamped record of deliveries, contractors and visitors on busy yards and industrial estates.

• Security alerts: flagging a vehicle on a site watch list, such as one linked to a previous incident on your premises, so it can be dealt with promptly.

• Supporting CCTV: linking plate reads to your wider CCTV system makes it quicker to find the right footage when something happens.

ANPR or ordinary CCTV?

A general CCTV camera covering a wide area is set up to show what is happening across a scene, not to capture a clear, readable plate on every vehicle. ANPR cameras are positioned and configured specifically for that job, and the software does the reading for you, so nobody has to scroll through hours of footage to find a registration.

In practice many sites use both: ANPR at the entrance and exit points, with standard CCTV covering the yard, car park and buildings.

Data protection: what the law expects

Because ANPR collects a lot of data very quickly, data protection needs thinking about from the start. The ICO's guidance makes several key points:

• A registration number is usually personal data, because it can lead back to the driver or registered keeper, for example when it is used to issue a parking charge.

• You should carry out a Data Protection Impact Assessment (DPIA) before installing ANPR, showing that it is necessary and proportionate for a clear purpose.

• Use the minimum number of cameras needed, and position them to avoid capturing vehicles you have no interest in, such as traffic on a neighbouring road.

• Keep the lists you match against accurate and up to date, and make sure the equipment is good enough to avoid misreads.

• Keep data only as long as your purpose requires, then delete it. The ICO gives the example of a gym with a two-hour parking limit, which should not hold on to records of compliant vehicles for long.

• Put up clear signs telling drivers that ANPR is in use and, where possible, who operates it, placed so they don't distract drivers.

• Have a process ready for subject access requests, and use a data sharing agreement if you share ANPR data with anyone else.

This article is general guidance, not legal advice.

How does this relate to police ANPR?

Police and law enforcement ANPR cameras feed into a single National ANPR Service, which is used to help detect and disrupt crime. That network runs under its own governance and is separate from a private system on your premises. If you install ANPR, your business is responsible for the data it collects.

You may also hear about the Surveillance Camera Code of Practice. Under the Protection of Freedoms Act 2012, relevant authorities, mainly the police and local authorities in England and Wales, have a legal duty to have regard to it when operating cameras in public places. Other operators are not legally bound by the code but are encouraged to adopt its principles voluntarily, and doing so is a sensible benchmark for good practice.

Questions to ask before you install

• What problem are we solving: access, parking, logging or security?

• Which entrances and exits genuinely need cameras?

• Who will manage the lists of permitted or flagged vehicles, and how often will they be updated?

• How long do we need to keep the data, and how will it be deleted?

• Should ANPR link to our existing gates, barriers, access control or CCTV?

• Have we completed a DPIA and planned our signage?

Need a hand?

If you are weighing up ANPR for a business site, Protect CSM can carry out a survey and design, install and maintain ANPR alongside CCTV, access control and gate automation across Hampshire and Surrey, including Bordon, Alton, Petersfield, Farnham, Liphook, Haslemere and Guildford. Call 01420 375376 or email info@protect-csm.co.uk.