The internet provides a remarkably quick and easy way to research and buy travel insurance. And buying the right policy on the net is almost certainly substantially cheaper than buying through a travel agent. A recent survey from the Research Department found that a single-trip policy for a family of four travelling to Europe would cost £92 with Thomas Cook for a minimum level of cover, and just over £18 with TravelPlan Direct for comprehensive cover.

Buying over the internet can be done in a matter of minutes by answering a few straightforward questions. You can pay instantly using a debit or credit card. You can usually reduce premiums by selecting to pay an increased excess, for example, or to opt out of personal belongings cover.

For a single trip to Europe for a week for one adult, TravelPlan Direct offered the cheapest cover at just £6. It covers £2m in medical expenses, £20,000 personal accident, £3,000 cancellation and £1,500 personal belongings.

For £8.50 CostOut's Super Plus policy will cover £10m in medical expenses and slightly more than TravelPlan for personal accident and personal effects.

It can be cost effective to buy annual cover if you plan more than two trips abroad a year. Again, TravelPlan Direct came out cheapest for annual cover for a single person within Europe at £29. JourneyWise's £29.95 Super Cover gets you £10m medical expenses, £100,000 personal accident, £5,000 cancellation and £2,000 personal belongings.

There are lots of insurers who specialise in cover for gap-year backpackers, although these won't necessarily offer the best value. You can often reduce the price you pay by adding exclusions to the policy. For example, Travel Insurance Club charges £175 for a 12-month world trip. However, this excludes baggage cover. Adding £1,000 of cover makes the premium £270.

If you're going to work abroad or participate in any hazardous activities such as white-water rafting or scuba diving, check the policy offers cover. Club Direct has a very comprehensive website. A worldwide trip, including the USA and Canada, for 365 days costs £223.20. This includes cover for working abroad, loss of passport, loss of baggage, cancellation and £10m in medical expenses.

• Lisa Bachelor is editor of Guardian Unlimited's Money section.

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