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uk Transport & mobility emergencies

What to do if…
a vehicle key fob or keycard stops working and you cannot unlock or start it

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy UK guide

Short answer

Get yourself and any passengers away from moving traffic or another immediate hazard. Then check the vehicle handbook or official manufacturer app for the emergency entry and backup starting procedure, and try a spare key before arranging roadside assistance.

Do not do these things

  • Do not force the door, pry at a window or insert improvised tools into the lock.
  • Do not use an online reprogramming sequence unless it is specified for your exact vehicle by the manufacturer.
  • Do not force open a fob or keycard that is swollen, badly damaged or wet.
  • Do not fit a battery unless it is the correct type and you can follow the vehicle or key instructions.
  • Do not attempt a jump-start unless the vehicle handbook allows it and you can do it safely.
  • Do not continue troubleshooting beside moving traffic when you can wait somewhere safer.
  • Do not leave a child, vulnerable person or animal locked inside while their safety may be at risk.

What to do now

  1. Deal with immediate safety first. If the vehicle is stopped on a motorway or other high-speed road, try to reach a place of relative safety. If it is safe and possible to leave the vehicle, exit on the side furthest from traffic and get well away, behind a safety barrier where one is available. If it is unsafe to exit, remain in the vehicle with your seatbelt fastened and hazard warning lights on, and call 999.

  2. If a child, vulnerable person or animal is locked inside and appears to be in immediate danger from heat or another hazard, call 999 now.

  3. Take the fob or keycard out of any signal-blocking pouch, protective wallet, metal container or crowded bag. Hold it by itself close to the vehicle and try again from a different position near the driver’s door.

  4. Try the spare key fob or keycard if one is available. If the spare works, use it for the immediate journey rather than continuing to dismantle or reprogramme the failed key.

  5. Check the vehicle handbook or official manufacturer app for an emergency mechanical key. Some fobs contain a removable key, and some vehicles have a door lock concealed behind a handle cover. Follow the instructions for your exact model.

  6. Once inside, follow the documented backup starting procedure. Your vehicle may require the fob to be held against the start button or another marked area, or the keycard to be placed on a specified reader.

  7. Replace the key battery only if the handbook or manufacturer instructions show how to open it and identify the correct replacement. Note the old battery’s orientation before removing it and stop if the casing does not open normally.

  8. Check for signs that the vehicle’s own electrical supply may be the problem. If neither key works and the interior lights, dashboard and central locking are also unresponsive, a discharged 12-volt battery or another electrical fault may be involved.

  9. Contact your breakdown provider, the manufacturer’s assistance service or an established automotive locksmith if the vehicle still will not unlock or start. Give your location, registration, make and model, explain whether you are outside or inside the vehicle, and be ready to show that you are authorised to access it.

What can wait

You do not need to decide now whether to replace or reprogramme the key, claim on insurance, change the vehicle’s security settings or book dealership repairs. Concentrate first on personal safety, authorised access and arranging roadside help or secure recovery.

Important reassurance

A failed remote does not necessarily mean the key or vehicle must be replaced. A depleted key battery, signal interference, physical damage or a problem with the vehicle’s electrical supply can produce similar symptoms, and your vehicle may have an emergency entry and backup starting method.

Scope note

This guide covers immediate safety, access and starting steps only. Key coding, replacement, security checks, electrical diagnosis and repairs may require the manufacturer, a breakdown provider, an automotive locksmith or a qualified repairer.

Important note

This is general information, not professional mechanical, electrical, locksmith or emergency advice. Follow the instructions for your exact vehicle and contact the emergency services when someone is in immediate danger.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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