Others hide sets under bins or in old tyres.

However, homeowners need to be aware that by doing so, they could be invalidating their home insurance policies. Even losing keys –  to doors, windows, sheds and garages – could have a negative impact.

If your home is burgled as a result of crooks happening upon a concealed key, or via a key left with a trustworthy associate, by definition they gain access to your property by simply letting themselves in.

This means that the burglary will leave no sign of forced entry – and most home insurance policies demand that there are obvious signs of forced entry before a claim can be lodged.

The Association of British Insurers (ABI) states that a break-in involving a key that has been lost, stolen or handed to a third party will be treated as an act of deception, not theft, meaning burglaries committed under such circumstances are not covered by standard home insurance policies.

If you review your home insurance policy, it may well specify some examples that qualify as ‘forced entry’, such as smashed windows, broken locks, forced doors and the like. Sadly, if this test is not met, it’s almost certain that a home insurance claim will be rejected – and the policy holder will have to fit the entire bill for replacing stolen goods, and repairing any damages inflicted by a burglar.

If you give a key to a lodger and they end up robbing you, it is unlikely you will be able to make a claim.

Fortunately, there are ways in which policyholders can protect themselves. Some insurance providers offer ‘lodger insurance’ as a supplement to home insurance – others ‘key insurance’ that covers the loss or theft of house keys, and ensures locks and keys are replaced promptly. In both cases, failing to augment a standard home insurance policy with such add-ons could result in bills of thousands of pounds, and they are worth considering as a result.

Below are some other non-policy tips preventing the inadvertent invalidation of home insurance.

• If your home is equipped with an alarm, it must be switched on every time you leave your home.
• Doors must be fully locked (whether mortice or cylinder) whenever you leave your home; many home insurers do not consider the breach of a latch to constitute forced entry.
• Windows must to be kept closed if you leave your property, or are in the bathroom or garden.
• If you’re going to be absent from home for an extended period (many home insurance policies will state a starting figure of around 28 days), you must inform your insurer –your cover may be adjusted as a result.