New rules have been introduced to help mobile phones get better signal indoors.
Ofcom put the new changes in place in April 2021 so that people can use a signal booster without needing a licence.
Mobile phone users are now able to buy a wider range of devices to help improve signal for surfing the internet or making calls.
Only two types of indoor mobile repeaters, also known as signal boosters, were previously legalised.
One was static mobile phone repeaters designed to improve coverage inside homes, offices and other buildings. They must not be used in other such as in a vehicle.
Another type was low gain mobile phone repeaters, which are allowed to be used to help coverage inside cars and other road vehicles - but not in boats or static caravans.
However, now they are allowing the unlicensed use of a further two types of boosters - provider specific repeaters and multi-operator repeaters.
Both these types of repeater may amplify the frequencies of more than one mobile operator at a time, provided they meet appropriate technical requirements specified by Ofcom.
The regulators said: "We won’t be endorsing or approving specific products; but to help people find legal mobile repeaters, we will publish a list of devices on our website that comply with the technical requirements."
Other ways to improve your indoor signal include using Wi-Fi calling, which allows you to connect to your broadband service to make calls.
Wi-Fi calling is available on a range of smartphones and allows you to use your phone without needing to download and use separate apps.
You might need to contact your mobile provider to activate the service.
