Low-paid manual workers are routinely being charged 10-20% more for car insurance than high-earning professionals such as solicitors, according to data from the AA.

It suggests insurers regard manual workers as higher risk, although employment status is just one of the factors they use when giving you a quote. The cocktail of risk factors includes age, gender, address and driving record.

Online car insurance quotes can show how the same person can be offered very different costs, just by changing their occupation.

It doesn't even have to be as specific as a particular job. One supermarket insurer offers "professional" applicants a quote for £713, while the same person, at the same address, who is a "manual" worker, is quoted £793.

So what are the best and worst jobs? According to the AA, the highest rates are attracted by sportsmen, particularly high-earning footballers. These well-off youngsters rate a clean sweep of risk factors: they're young, male, drive expensive high-performance cars, have little no-claims history and might have clocked up a few speeding points.

All these send premiums rocketing higher than a David Beckham penalty - and there are claims some premiership players can pay in excess of £10,000 per year. But at the other end of the spectrum, the cheapest insurance is likely to be paid by accountants. As well as being careful with other people's money, they can also be careful with their own.

The AA says that other workers in this cheaper group include civil servants, IT consultants, shop assistants and solicitors.

This isn't any type of moral judgment, says the AA, but a statistical reflection of relative risk based upon the previous claims. Low-charging groups are simply seen to be exposing their cars and themselves to fewer risks.

The higher risk rating might have nothing to do the way the car is driven, rather where it was left, says the AA.

For instance, publicans who leave their car near the pub are exposed to greater risk from boozed-up customers. Nightclub staff are similarly seen to have a higher risk from leaving their car in high crime urban areas at night.

The type of lifestyle associated with an occupation can also be taken into account. Airline cabin crew are charged more because they are working irregular hours, driving home after long flights and leaving their cars unattended for long periods.

As such, the AA says their might be loaded by an extra 5% while accountants might expect a reduction of 7%.

But there are also big differences between insurers in how they interpret people's jobs.

The AA says that from a selection of 11 companies, there were quotes showing anything from £6 to £60 be tween the annual policies for an accountant and airline cabin staff.

There were also 15 insurers, the AA found, charging exactly the same, regardless of occupation.

If you think you might lose out on the distinction between professional and manual worker, there are insurers that go into much finer detail. And again, examining online insurance quotes, can give an insight into whether you're going to be penalised for your job.

As an example, using the website of a major insurer, a 30-year-old man, living in London and driving a family saloon, is quoted £481 per year if he's a solicitor or a librarian, but that rises slightly to £498 if he's a school teacher. But this same person, when identified as working in a fast-food restaurant, is quoted £550.

An even higher quote is given if the same fictional applicant is working as a hospital porter with a price of £573, a hefty £92 more than the solicitor.

When the occupation is changed to "unemployed", the online system refused to give a quote.

It's also worth checking to see if there are specific discounts for your jobs. Staff in the health and education sectors are likely to be offered cheaper car insurance by Zurich this autumn, as it re-introduces a discount to attract more public sector workers.

How big a risk are you?

Low risk
Shop Sales Assistant
Civil Servant
Admin Clerk
IT consultant
Accountant
Solicitor
Mechanic - providing SDP only

Medium risk
Sales Agents/Insurance agents Painter/Decorators/Builders
Self-employed
Electricians

High risk
Self-employed
Commercial Traveller
Casino Employee
Gaming/Night-club employee
Security guard
Publican
Journalist

Very high risk
Fashion photographer
Models
Professional sportsperson
Casino owner
Night-club/gaming owner
Entertainment profession