Driving other cars is a crumb of cover, not a second policy

The theory of driving other cars extension is well covered elsewhere. This is about the version you meet in practice.

What the extension actually gives

Where it exists, a driving other cars extension lets the policyholder drive a vehicle they do not own in an emergency. The cover provided is almost always third party only, meaning injury to others and damage to their property.

Damage to the car you are actually driving is not covered, however comprehensive your own policy may be. That is the point most people misunderstand, because comprehensive feels like a level of cover that should follow the driver. It follows the driver only for liability, and liability is the part the law requires rather than the part that protects you.

Who has it and who does not

The extension is generally restricted to the named policyholder, so a named driver on the same policy usually does not have it. Insurers commonly impose a minimum age, often well above the licensing age, and exclude certain policy types entirely.

It is frequently absent from telematics policies, from many young driver policies and from a growing number of standard ones. Some insurers have withdrawn it altogether, and the change appears at renewal without being announced prominently. The only reliable way to know is to read the certificate of motor insurance itself rather than a summary or memory.

The conditions attached

The vehicle must normally be driven with the express permission of its owner, which is a low bar but a real one. Many wordings require the vehicle to be insured by someone else already, so an uninsured car cannot be driven under it.

In practice, the vehicle usually must not be owned by you, hired to you or available to you under a hire purchase agreement. Some wordings restrict use to emergencies, and a few define what an emergency is in a way that excludes convenience. A breach of any of those leaves you driving without insurance, which is a criminal matter rather than a coverage dispute.

What happens after an accident

If you damage the other car, your third party cover pays the other party while the car you drove is repaired at somebody expense. That somebody is usually the owner, who then claims on their own policy and loses their no-claims discount. Your own policy will normally treat the incident as a fault claim, so your discount is affected too.

A single borrowed journey can therefore cost two people their discounts and produce an awkward conversation afterwards.

Where the owner is uninsured, the position is worse again, and in some jurisdictions the vehicle may be seized.

Better ways to borrow a car

Temporary insurance in your own name, bought by the day or the hour, is widely available in several markets. Being added as a named driver on the owner policy is the traditional route and is often cheap for a short period.

Some insurers allow a temporary additional driver to be added online for a small administrative fee. Each of those routes can provide comprehensive cover on the borrowed vehicle, which the extension never does. None of this is a recommendation of any product; availability, price and rules differ considerably by country.

Checking before you drive

Read your certificate, not the policy booklet summary, because the certificate is the document that states who may drive what. Look for the words third party only, since their presence tells you exactly what you would be relying on.

The useful part is this: confirm the age condition and whether the extension survives on your current policy type after the last renewal. Ask the owner whether the car is insured, and treat any hesitation as a reason not to drive it. If in doubt, buy temporary cover; the cost is small against driving uninsured by accident.

The takeaway

Read the certificate before you borrow a car, and assume the extension is gone unless the document in front of you says otherwise.

The version you keep doing is the version that works.