THE LAW
The driver must be insured
GOV.UK says that even if the vehicle is insured, you can be penalised if you are not correctly insured to drive it: a £300 fixed penalty and 6 points.
See the numbersWHAT THE RULES SAY
The car is insured. Are you?
In the UK it is illegal to drive on a road without at least third party insurance, and that applies to the driver, not just the car. Borrowing a friend's car is fine, as long as a policy actually covers you to drive it.

£300 + 6 penalty points if uninsured
THE SHORT ANSWER
Three things that catch people out
when they borrow a car.
THE LAW
GOV.UK says that even if the vehicle is insured, you can be penalised if you are not correctly insured to drive it: a £300 fixed penalty and 6 points.
See the numbersYOUR OWN POLICY
MIB says driving other cars cover is not always included and, where it is, is often third party only, and not usually allowed if you are under 25.
Check your situationTHE BETTER ROUTE
For regular use, MIB suggests being added as a named driver on the car's policy. For occasional use, a short-term policy is an option.
Before you driveGeneral information only, not financial advice. For advice on your own situation, speak to a regulated financial adviser or a free money-advice service.
CHECK YOUR SITUATION
Pick the situation closest to yours to see what the guidance says. The bar shows how likely it is that you would not be covered without changing anything.
Based on MIB guidance on common insurance myths and being properly insured. General information, not legal or financial advice: check your own policy.
TWO NUMBERS WORTH KNOWING
One figure on the penalty,
one on how many cars are uninsured.
£300 + 6 points
Fixed penalty for driving a car you are not insured to drive
If the case goes to court, GOV.UK says you could get an unlimited fine and be disqualified from driving. Police can also seize, and in some cases destroy, the vehicle.
PENALTY · GOV.UK
335,000
Uninsured vehicles on UK roads on any given day
MIB, which handles claims involving uninsured and hit-and-run drivers, says every 20 minutes someone in the UK is the victim of an uninsured or hit-and-run driver.
UNINSURED VEHICLES · MIB
Third party insurance is the legal minimum. It covers damage or injury to other people, vehicles, animals or property, but not repairs to the car you are driving.
FOUR CHECKS BEFORE THE KEYS
None of these is complicated. They are about making sure a real policy covers you, in that car, for that trip.
Look for a driving other cars section and its limits: age, level of cover and which cars it excludes.
Driving other cars cover needs the car itself to have valid insurance. GOV.UK points to askMID to check a vehicle.
With third party only cover, damage to your friend's car is not covered. One ombudsman case turned on exactly that.
If no policy covers you, MIB says to buy one, or be added as a named driver, before you get behind the wheel.

IF SOMETHING GOES WRONG

In a Financial Ombudsman decision, a driver borrowed a friend's comprehensively insured car using the driving other cars section of his own comprehensive policy. That section gave third party cover only, so there was no cover to repair the friend's car.
After an accident causing damage or injury, GOV.UK says you must give your name and address and the vehicle registration, plus the owner's name and address if the car is not yours. If you do not give your details at the time, report it to the police within 24 hours.
Questions
Not automatically. GOV.UK says that even if the vehicle is insured, you can be penalised if you are not correctly insured to drive it. Most policies only cover the policyholder and named drivers.
Sometimes. MIB says driving other cars cover is no longer often included as standard, usually comes with conditions such as age limits, is often third party only and is intended for emergencies.
Fronting is putting someone else down as the main driver to get a cheaper price when you are the main user. MIB says it is a type of fraud that is illegal and invalidates the policy.
GOV.UK says police could give a £300 fixed penalty and 6 points. In court you could get an unlimited fine and be disqualified, and the vehicle can be seized and in some cases destroyed.
Only if the policy covering you includes damage to that car. Third party cover pays for damage or injury to others, not the car you are driving.
Sources
ABOUT THIS NAME
friendborrow.com is part of the DoodleSale portfolio. It isn't in an auction right now, but you can ask about leasing it.