It might mean finding a replacement vehicle, in which case you will need instant cover, and temporary car insurance is the best way to cover this.
When you might need temporary car insurance
Although it may not have been something you have needed to date, there are many occasions when you might need temporary cover when driving on public roads. If your vehicle is in the garage for repairs, but you urgently need to make a trip to a relative, you may need to borrow a car from a family member or a friend. It is unlikely you will be insured to use that vehicle, and so you will need to take out some short-term cover.
On some occasions, such as when they are going away to study, younger members of the family may need to borrow their parents' car. Alternatively, they might want to use the car for a day trip or a weekend away. In this case, it may be cheaper, and quicker, to take out temporary cover for them rather than add them to an existing policy.
In another scenario, you may be moving home and need to borrow a friend's van, or a large car that will accommodate items of furniture. Again, temporary car insurance will make this a viable option.
Business use and temporary car insurance
There are occasions when your own vehicle may not be insured for a journey that you need to undertake. This may well be the case when you use a car with private use insurance for a journey connected to your work, defined in the insurance industry as business use.
You may not have any other option in these circumstances but to use your private vehicle. Were you to be involved in an accident during such a journey, your regular 'social, domestic and pleasure' use policy would not cover you for any damage to the vehicle or loss of property. Regardless as to how long you need to use your private vehicle for business purposes, from a few hours to a few weeks, it is possible to obtain the cover you need at a price to suit your wallet.
Buying a new car and temporary car insurance
If you have bought a new car and want to get it onto your driveway as quickly as possible, you can take a temporary policy out to cover you whilst you research and organise the most appropriate policy for longer-term cover. Alternatively, you might want to confirm your choice with a test drive if you are buying privately (most dealers will have suitable insurance). In this case, you may need temporary cover to drive the vehicle.