New rules ban virtually all hand-held use of mobile phones on Britain’s roads, in what Transport Secretary Grant Shapps described as a “zero-tolerance approach”.
New legislation means making phone calls and texting are not the only functions banned when behind the wheel.
Taking photos or videos, scrolling through playlists and playing games will also be prohibited.
Anyone caught using their hand-held device while driving could face a fine of up to £1,000 as well as six points on their licence.
Department for Transport figures show 17 people were killed and a further 114 were seriously injured in crashes on Britain’s roads in which a driver using a mobile was a contributory factor.
Drivers will still be allowed to use their phones to make contactless payments, such as at drive-thru restaurants, as long as their vehicle is stationary.
They can also use their device as a sat-nav if it is secured in a cradle.
Mr Shapps said: “I will do everything in my power to keep road users safe, which is why I am taking a zero-tolerance approach to those who decide to risk lives by using their phone behind the wheel.
“I’m ensuring anyone who chooses to break this vital law can face punishment for doing so, and we’ll continue our efforts to ensure our roads remain among the safest in the world.”
AA president Edmund King said: “This is a much-needed toughening of the rules to help make our roads safer.
“The best thing to do is to convert your glovebox into a phone box. We all need to keep our hands on the wheel and our eyes on the road.”
An £800,000 Think! awareness campaign will run until the end of April.
An RAC survey of 2,000 UK drivers conducted last week indicated that 43% of motorists are not aware of the changes being introduced, and 45% believe they will not be effective.
RAC spokesperson Rod Dennis: “The dial really needs to be turned up when it comes to enforcement, and that means police forces having the resources and technology they need to more easily catch those drivers that continue to flout the law.