With most insurers, the size of discount you can achieve increases until you have built up five NCD years, at which point the maximum discount percentage is achieved. Despite this, some companies continue to recognise if you go further years without making a claim - but they don't increase the size of your discount (or at least not by much).

However, it can still be helpful. If your insurance company recognises up to, say, nine years of claims-free driving and you have an accident, you might lose two years and drop back to seven. As that's still higher than five, making a claim would not jeopardise your discount.

Other companies will always drop you back to three years after an accident, regardless of your number of years claims-free.

The amount of discount earned increases with each year of claim-free driving.

So after one year you might get 30%, with the percentage increasing each year until you get 70% NCD after five years.

Most firms offer a maximum NCD of 70%, although some offer 75% or 80%.

Some insurance companies offer drivers with no NCD an accelerated bonus scheme, which awards a year's NCD after 10 months claims-free driving.

After 10 months, you can either renew with the same firm, or move to another firm with the one-year bonus intact.