How do I use dashcam footage after a crash, and is a dashcam even legal?

How to protect the file before it is overwritten, who to give it to and in what form, what the law actually says about recording in a vehicle, and the audio question people get wrong.

Difficulty: beginner
Time: 20 min
Read: 5 min
Safety: caution

Short answer

Save the file immediately — most dashcams loop and will overwrite it, and the emergency lock button only works if the impact triggered the sensor. Copy it off the card to two places before anything else, note the exact time, and give the original file to your insurer, unedited. Dashcams are legal in the UK, including on the windscreen provided they do not obstruct your view, and recording audio in your own car is lawful — but tell passengers, and be careful about publishing.

A dashcam is only useful if the footage survives the twenty minutes after the incident, and that is where most of them fail. Loop recording means the card is a rolling buffer: unless the file is protected, it will be overwritten, sometimes within an hour on a small card. The G-sensor is supposed to lock the file automatically on impact, but it is calibrated for a collision and frequently does nothing for a near miss, a road rage incident, or a low-speed shunt in a car park. The habit worth building is simple and manual: stop the camera or pull the card as soon as it is safe.

Safety

Do not review footage at the roadside while traffic is passing, and never argue about liability at the scene — exchange details, take photographs and leave the determination to the insurers. Publishing footage of an incident online before an insurance or police process concludes can prejudice it and can expose you to a claim, so save it and hand it over rather than posting it.

Step by step

Protect the file before anything else.Once everyone is safe and out of the traffic, either press the manual lock button, stop the recording, or switch the camera off and remove the card. Do not leave it running while you exchange details for twenty minutes — that is exactly how footage is lost.
Copy it off the card twice.Onto a phone or laptop, and into cloud storage or an email to yourself. Memory cards fail, and a card that has been recording continuously for a year is not a safe place to keep the only copy of something important.
Keep the original file exactly as it is.Do not trim it, do not convert it, do not add annotations, and do not upload it to a service that re-encodes it. Insurers and police want the unaltered original with its embedded timestamp and, where present, its GPS and speed metadata. Provide clips as extras if you like, but keep the original.
Check that the camera's clock was right.A wrong date or time on the footage undermines it. Many cameras lose the time when unplugged for a while, and some set it from GPS automatically. Check it now, and note if it was wrong so you can explain the discrepancy rather than being caught by it.
Give it to your insurer, promptly.Tell them at the point of reporting that you have footage. It frequently settles liability disputes on the spot and prevents a fifty-fifty split on a claim you would have won. Follow their instructions on format and transfer.
Report it to the police separately if it shows a serious offence.Most UK forces operate an online portal for submitting driving footage — often under a national scheme name — where you upload the file and a statement. There are usually time limits for submission, so do not sit on it for weeks.
Understand where the law actually sits.Using a dashcam is lawful in the UK. It must not obstruct your view of the road, which is why the standard position is high on the windscreen behind the mirror. Filming on a public road is lawful. Where care is needed is in what you then do with the footage.
Handle audio and publishing carefully.Recording audio in your own vehicle is lawful, but tell passengers — a private conversation recorded without knowledge is at best a discourtesy and at worst a problem. If you use the car for work, or carry paying passengers, data protection obligations can apply. And publishing identifiable footage online before a process concludes can prejudice it and expose you to complaint.

Common mistakes

Posting the footage on social media before the claim concludes — It can prejudice an insurance or police process, it identifies other people who have not consented, and it occasionally attracts a complaint against the person who posted it rather than the driver in the video.
Editing the clip down before sending it — The moments before and after an incident are often what decide liability. An edited file also invites the argument that something has been left out.

If it doesn't work

Footage has been overwritten

Cause: Loop recording continued while you dealt with the scene — Fix: Check the locked or protected folder — the G-sensor may have saved it there. If not, it is gone. Build the habit of stopping the camera first next time.

File plays on the camera but not on a computer

Cause: A proprietary container, or a partially written file — Fix: Most manufacturers supply a free player. Give the insurer the original file and tell them which camera it came from rather than trying to convert it.

The other driver denies what the footage shows

Cause: A liability dispute — Fix: This is exactly what the camera is for. Give the file to your insurer and let them handle it; do not send it to the other party directly.

Camera was recording but the card is empty

Cause: A failed or counterfeit memory card, or a card that was never formatted in the camera — Fix: Test the camera regularly by watching a recent file. Use a high-endurance card and reformat it in the camera every month or two.

Insurer says the footage is inadmissible

Cause: It has been edited, or the timestamp is wrong — Fix: Always supply the unaltered original. If the clock was wrong, say so up front with an explanation rather than letting it be discovered.

A parking incident happened and there is nothing recorded

Cause: Parking mode not enabled, or the voltage cut-off had already switched the camera off — Fix: Check the settings and the power arrangement. The catalogue's guide on powering a dashcam covers why parking mode so often is not actually running.

Questions people ask

Are dashcams legal in the UK?

Yes. There is no law against using one, and filming on a public road is lawful. The constraints are practical: it must not obstruct the driver's view, the cable must not create a hazard, and what you do with the footage afterwards is where data protection and defamation considerations arise.

Will a dashcam reduce my insurance premium?

Some insurers offer a discount for having one and a few require the footage to be made available after any incident. It is worth asking, though the discount is usually modest — the real value is in not being held liable for something that was not your fault.

Can I submit footage of someone else's bad driving?

Yes. Most UK police forces accept public submissions of driving footage through an online portal, and they do act on it. Submit within their stated time limit, include a statement, and keep the original file — do not publish it while they are considering it.