Nearly half of British households are making basic security mistakes - leaving them vulnerable to thieves.
According to Co-op Insurance, more than 13 million households - 48% - are putting their property and belongings at risk, particularly when they go on holiday.
Over 500,000 households in the UK are sharing their holiday plans on social media, advertising their empty homes to thieves.
And, as Caroline Hunter, head of home insurance at Co-op Insurance, says, "As tempting as it is to check in at the airport on your phone, or share pictures around the pool whilst on holiday, it lets followers know a little too much information about when you'll be out of the country and when your property will be left empty."
If you really must share your holiday plans, she says, think carefully about who will be able to read your posts, and make sure you check your privacy settings. Check that the GPS or location services on your phone are switched off, so your posts don't say where you are currently located.
Meanwhile, almost a fifth of people keep their sheds unlocked while they are away, 16% leave things out in the garden that can be used to break a window and 15% have left the house with the windows open.
"Most burglaries are opportunistic and many can be prevented by taking basic steps to protect your home," says Jim Maddan, chair of Neighbourhood Watch.
"We strongly recommend making your home look occupied when you leave it for both short and long periods, and if you're out in the garden and you cannot see the doors or windows of your property then they should be shut and locked."
Neighbourhood Watch advises locking your doors and windows every time you leave the house. Keep outbuildings such as sheds and garages locked at all times, along with garden and side gates.
Ladders and tools should be locked away, so they can't be used to break into your home.
And if you're going away, make the house look as though it's still lived in by cancelling milk or newspapers and asking a neighbour to put the bins out and bring them in.
Install a burglar alarm and be sure to use it, along with security lighting. And don't leave valuable items lying around the garden or near a ground floor window.
The UK's top security mistakes
1. Keeping sheds unlocked
2. Leaving out something that can be used to break a window
3. Leaving windows open
4. Having deliveries hidden in the garden/outside the house
5. Leaving ladders in the garden
6. Hiding keys in the garden/under a plant pot
7. Posting on social media when going on holiday
8. Leaving tall items under a window