What do oil rig workers, DJs and bar staff have in common? They are all treated as non-standard occupations by insurance companies and pay considerably more for motor insurance as a result.

Insurers are reluctant to reveal exactly what criteria they use to define a high-risk occupation, but the assessment is partly based on claims history data and partly on assumptions about the driver's lifestyle.

A lot of people have established themselves with an insurance company before they move into a "dangerous" walk of life. Those who have acquired the high-risk tag and approach an insurance company for the first time can expect to be refused a quote or charged a high loading on their premium.

Liability claims tend to be higher in the entertainment business, especially in the high-income bracket, according to one insurer. The perception is that high rollers are likely to have other high rollers in their car and any claims for personal injury or loss of earnings would be above average.

Hibernian's philosophy on this issue is to reduce exposure to those in particular occupations who find themselves on the road during the high frequency accident hours of 11 p.m. to 3 a.m.

So should oil rig workers and bar staff be offended by their classification? Mr Dick O'Driscoll of Hibernian says it is not a comment on the behaviour of the individual but a matter of driving patterns.

He says there is room for interpretation with regard to defining occupation and it could depend on how the case is represented. Mr O'Driscoll cites an example of an orchestra musician availing of provided transport, who would not be treated the same as a gigging musician.

Even a publican, also a high-risk category, can get the company to listen, according to Mr O'Driscoll, if they can establish a bona-fide case that the normal occupational exposure does not apply to them.

"We would be tough about it, we would want black and white answers on the use of the vehicle but we do try to understand individual cases," Mr O'Driscoll says. The prospect of having to pay a heavy loading can lead to some drivers side-stepping the thorny question of occupation. Slightly changing your title from musician to music teacher or model to beauty assistant can mean much cheaper premiums, and the temptation is hard to resist for some.

An insurance contract is entered into under the principle of "utmost good faith" and the insurance company will take what the policyholder says at face value.

Pretending to be working in a different capacity is misrepresentation and the policy could be declared null and void. This could mean the insurance company would not pay out in the case of an accident. One insurer tells Family Money it is unlikely that drivers will be caught out on this score but others warn that it is dangerous to make a false declaration.

A spokesman for St Paul Ireland Insurance says it is very important that people adequately describe their occupation, as assessors will establish if any discrepancies arise in the case of a claim.

St Paul specialises in "non-standard" motor insurance and has well-known personalities on its books. Before its arrival in the Irish motor insurance market in 1993, high-risk occupations were mainly taken on by insurers through "grace and favour".

Along with "non-standard" occupations, St Paul provides quotes for drivers with highperformance cars, a claims history, motor convictions or a medical condition. The company says premium prices are based on data built up over a period of time. It is difficult to get an insurance company to be more specific than that.

The range of premiums for motor insurance is enormous - anything from a couple of hundred pounds to four or five thousand pounds. Naturally, nobody wants to be on the expensive end of that scale.

Mr Philip Behan of Royal & Sun Alliance explains that what the underwriter is trying to do is to visualise the risk exposure. "Lots of factors impact on that and occupation is only one part of the equation," he says.

He says actuarial data concentrates on class of use such as social or commercial rather than occupation, and that people could explain if they considered themselves to be an exception to the rule.

Some of the occupations on the insurers' list that will prompt a sigh or a laugh from customer service staff are more obviously risky than others.

It's clear that any job that involves late-night socialising or easy access to alcohol will not be a welcome risk.

One insurer says embassy employees could be difficult to track down after an accident. As for entertainers, insurers give the example of the concert pianist with a broken arm or a model with facial injuries.

There is also a reluctance to take on someone who drives for a living. This is a problem for self-employed drivers who also use the commercial vehicle for domestic and social purposes.

Perseverance and deep pockets seem to be the key requirements for those in non-standard occupations. If you do defy the stereotype for your walk of life, it is worth making your case to the insurer or getting a broker to do it for you.

The bottom line for most non-standard drivers remains unchanged. At the end of many phone calls, expect to pay more for motor insurance.