According to recent research, one in 10 of us has had our home burgled. More alarmingly perhaps is that one in three people admit to leaving doors unlocked when they leave the house and six per cent hide spare keys near their front door.

While some may think leaving doors unlocked is a trivial action, by not securing your property efficiently, you’ll not only risk burglary, you’ll also risk invalidating your home insurance.

If there is no evidence of a forced entry and it appears a burglar strolled in through an unlocked door, your home insurer may refuse to meet your claim. They might say you failed to take appropriate measures to properly secure the property and therefore deem your policy invalid. If in doubt, check the details of your contents insurance policy to see what conditions apply.

In London, The Metropolitan Police has launched a ‘lock before you leave’ campaign urging Londoners to lock their doors and windows when leaving their home.

The campaign is in response to statistics that reveal over 5,000 homes were broken into last year by burglars simply walking through unlocked front doors.

Police say that many people forget to lock up properly, leaving their property vulnerable to burglary. It’s an easy thing to do, especially if you’re in a hurry, but it does make a burglar’s job much easier. Figures showed that thirteen per cent of all burglaries were ‘walk-ins’ and in sixty-four per cent of these cases, criminals had got in through the front door.

Security is an important factor for home insurance providers, as it helps them determine how likely you are to make a claim. With this in mind, being vigilant and installing good security features might result in lower premiums. Multi-point locking systems on all windows and doors are often looked upon favourably by insurers, as are burglar alarms.

You should always read the small print of any contract you sign, and insurance should be no exception. Knowing what you are and are not covered for under your insurance policy should be the first thing you ask when purchasing home protection.

Below are ten examples that could invalidate your home insurance:

1. Leaving windows open or not locking windows where locks are fitted.

Always close and lock windows in unoccupied rooms. During the summer, use a fan or a/c rather than exposing yourself to theft.

2. Your insurer may reduce or refuse any pay-out if your locks are described inaccurately on the policy.

Correctly describe the locks when filling in your home insurance application form. Inform your insurer whenever locks are upgraded.

3. If a burglar is able to gain unforced entry to your home, your insurer may not pay out on your full claim.

Never leave spare keys hidden outside the house; if a burglar uses them, your policy may be void.

4. If you informed your insurer that you have a burglar alarm, but do not activate it when the house is unoccupied the insurer may reduce of refuse to pay-out.

Activate your alarm whenever you leave your home, even if it’s just for a few minutes.

5. Thefts must be reported to the police within 24 hours in order to obtain a crime number. Failure to do so could result in claim rejection.

Report all thefts to the police as soon as possible and get a crime number.

6. Failure to secure valuables in the garden that are not specifically covered by the policy (barbeques, lawn mowers etc.)

Check what is insured for use in the garden. Extend your policy to include nvaluables likely to be outside during hot weather. Secure valuables in a garage, secure shed or your house when you’re not around.

7. Not securing tools that are then used to break into the house (ladders, hammers, wrenches etc.)

Secure tools within a garage, secure shed or your home.

8. Failing to notify your insurer that builders are on-site. If you suffer accidental damage (e.g. damage to the property, burst pipes etc.) the insurer may either refuse to pay for the claim, or only pay a reduced amount.

Tell your insurer when builders will be on-site. This may incur a temporary increase in your premium to cover any accidental damage.

9. Any claim made during a period when the house is left unoccupied for more than 30 consecutive days may be voided.

Arrange for someone to stay one night within any 30-day period to reset the count.

10. If you use your home as a place of business, an increase in visits from people is assumed, thus increasing the likelihood of theft and other associated claims.

Even though your premiums may increase slightly, declare to your insurer from the outset that you are using your home as a base for your business.

Adam Powell is head of operations at Policy Expert