A key safe is a secure box with a combination-code used for keeping a spare key for anyone who has multiple visitors but has difficulty getting to the door to let them in.
The Supra C500 key safe is police approved. Contact your home insurance provider for further advice.
There are a number of organisations in Norfolk that provide key safes in Norfolk, broken down by district council area.
South Norfolk District Council handyperson service
Broadland District Council
Great Yarmouth District Council Safe at Home
(Costs and conditions may apply)
Private companies also offer key safes. Take a look at Norfolk Trusted Trader.