The Circuit launched in 2021 and is the national defibrillator network which maps defibrillators across the UK, connecting them directly and automatically to each ambulance service. *Always dial 999 immediately in an emergency and they will direct you to your nearest defibrillator.

Defibrillators can often be found in or outside public places such as:

• train stations
• airports
• supermarkets
• shopping centres
• gyms
• village halls

Call 999/112 for an ambulance, and give the emergency operator the number of the defibrillator written on the cabinet. The ambulance service will have the code to open the defibrillator cabinet.

It’s useful to check how to access your local defibrillator before having to use it.

There is no legal requirement for you to have a defibrillator in your workplace, but your risk assessment might identify that there is a need for one. They are especially important if your workplace is remote, or if there could be a significant delay in the ambulance service getting to the casualty.

Having an on-site defibrillator is also valuable if:

• you have an ageing work force
• there has been a history of cardiac conditions in the work force
• your workplace is frequently visited by large numbers of the general public, such as a supermarket.

If you are considering buying a defibrillator, read our defibrillator buying guide.

Yes - All makes of defibrillator will provide voice instructions or visual prompts instructing you what to do, from performing CPR to attaching the pads.

All defibrillators check the heart rhythm of the person to determine if a shock needs to be administered. If it is an automatic defibrillator, a shock will be delivered automatically. If it is a semi-automatic defibrillator, the voice instructions will prompt you to push a button to deliver a shock.

Any defibrillator can be used by anyone with no training. However, taking defibrillator training will increase your confidence to be ready to act in an emergency.

Yes, you should start CPR as soon as possible.

It is best to learn CPR in advance, so you know exactly what to do. Learn from our CPR how-to guide or take a training course.

Bystander CPR and use of an automated external defibrillator (AED) can increase the chances of survival by two to four-fold from sudden cardiac arrest. (Information from Resuscitation Council UK)

The defibrillator will indicate when to start and stop CPR, and guide you through how to do CPR.

Important: do not touch the casualty when the defibrillator administers a shock.

No. If a person is not in cardiac arrest the device will not administer a shock, even if you press the button, as it has detected a heartbeat.

By using a defibrillator, you increase their chances of survival. For more information on why using a defibrillator is important, please read this section on our Defibrillator guide for first time buyers page.

There is nothing to indicate that defibrillators should not be used during pregnancy.

Still use the defibrillator. If you see of feel a device under the chest skin, do not place the pad directly over it.

If the casualty has a patch on their chest, remove it before applying the defibrillator pads.

Yes, but ensure:

• you dry the casualty’s chest before using
• there is no direct contact between the rescuer and the casualty when the shock is delivered.

If chest hair prevents good contact between the skin and the pads, shave it off.

Some defibrillators are supplied with razors. If you are responsible for maintaining a defibrillator, ensure a razor is available as part of the rescue kit.

Defibrillators will record when they are used on a memory chip/module. The information collected is:

• the heart rhythm at the time the pads were placed on the chest,
• if the patient was shocked and the result of the shock being delivered.

This information may be downloaded following the event. This is used by relevant bodies, as part of their research programmes and for statistical evidence of the effectiveness of defibrillators.