ALPR stands for automated (or automatic) license plate recognition, or reader. LPR means the same thing without “automated,” and ANPR (automatic number plate recognition) is the British and international name. All three describe cameras and software that read vehicle plates and compare them with lists of plates of interest.
What ALPR, LPR and ANPR stand for
| Term | Stands for | Where it is used |
|---|---|---|
| ALPR | Automated (or automatic) license plate recognition, or reader | The most common term in US police work, statutes and policies. |
| LPR | License plate recognition, or reader | Common in the US. Means the same as ALPR; “automated” is simply dropped. |
| ANPR | Automatic number plate recognition | The British term, also used across Europe, Asia and the Commonwealth. |
| ALPR vs LPR | No technical difference | Statutes and vendors choose one or the other. Both describe cameras and software that read plates automatically. |
How the terms relate to the technology
All three names describe one chain of steps: a camera captures an image, software finds the vehicle and plate, converts the characters to text, and compares the result with lists of plates of interest. Modern systems use AI (deep learning) for the detection and reading steps. For the step-by-step version, see how AI license plate recognition works.
People sometimes say “license plate scanner,” “plate reader” or “tag reader.” These are informal names for the same thing. Plate recognition is not facial recognition: it reads vehicle plates and, in some systems, vehicle attributes such as color and type. Cameras that also record video can capture people incidentally, which is why policies should cover video as well as plate data.
Glossary: the terms you will meet
| Term | Meaning |
|---|---|
| Read | One detection of a plate by a camera, with a time, a place and often an image. |
| Hotlist | A list of plates of interest (stolen vehicles, wanted persons, missing persons). A match triggers an alert. See hotlists explained. |
| Hit or alert | The notification created when a read matches a hotlist entry. A person must verify it before acting. |
| NCIC | The FBI’s National Crime Information Center, a national database of criminal-justice records, including vehicles and plates. See NCIC and plate readers. |
| CJIS | The FBI’s Criminal Justice Information Services division and its Security Policy, which sets security rules for systems that touch criminal-justice information. |
| BOLO | “Be on the lookout”: an agency notice about a person or vehicle, sometimes entered into a hotlist. |
| OCR | Optical character recognition: the step that converts the image of a plate into text. |
| False positive | An alert that turns out to be wrong, for example because of a misread character or a stale hotlist entry. |
| Retention | How long reads and video are kept before automatic deletion. See policy and data retention. |
| Audit log | A record of who searched the data, when and why. |
| Fixed, mobile, portable | Fixed readers sit on poles; mobile readers ride in patrol vehicles; portable or rapid-deploy readers are moved between locations. |
| Vehicle attributes | Descriptions such as color, type and make that help find a vehicle when the plate is missing or misread. |
| Edge vs. cloud processing | Whether the AI runs in the camera or in a remote data center. Each has trade-offs in speed, bandwidth and data control. |
Why the name matters in law
The name matters more in law than in engineering. Statutes define an “ALPR system” in their own words, and the definition decides which cameras and data the rules cover. For example, Illinois’s law (625 ILCS 5/2-130) defines both the system and “ALPR information.” When you read a statute or write a policy, use its definitions, not a vendor’s. See license plate reader laws by state.
Frequently asked questions
What does ALPR stand for?
Automated (or automatic) license plate recognition, or reader. The “R” is used for both “recognition” and “reader.”
Is LPR the same as ALPR?
Yes. There is no technical difference. LPR drops the word “automated.”
What is ANPR?
Automatic number plate recognition. It is the term used in the UK and many other countries for the same technology as ALPR.
What is a license plate scanner?
An informal name for a license plate reader. It is not a handheld scanner of people or phones; it reads vehicle plates.
Does ALPR use facial recognition?
No. ALPR reads plates and, in some systems, vehicle attributes. Cameras that record video can capture people incidentally, so policies should address video and any other analytics separately.