New rules mean drivers caught using a phone within two years of passing their test will have their licence revoked.
The laws apply to drivers in England, Scotland and Wales.
It's just part of tougher punishments cracking down people using hand held phones while driving.
But where do you stand if you use a cradle or "hands free" whilst driving? We've been asking an expert to clear up some of the grey areas.
From today picking up your phone while driving - even if you're stopped in traffic or at lights - will get you at least six points.
Police forces have begun a seven-day crackdown, with extra patrols and an "increased focus" on stopping people using their phones while driving.
The AA told Newsbeat if you are using your phone while it is secured in a cradle it may be slightly different.
That's because technically the device is not handheld.
"But if you are involved in a collision as a result you could be prosecuted for driving without due care and attention," they said.
"That carries an even greater penalty, particularly if you injure or kill somebody, in which case you would be prosecuted for causing death by dangerous driving."
They say "your full focus should be on driving" every time you get behind the wheel. Ideally you should switch your phone off, or put it away, if you're driving.
We asked the motoring group some specific questions about using your phone in a cradle.
Can you use it as a sat-nav?
"It should be programmed with the route before you set off.
"If it pops up with a message which requires just one press of a button, such as 'A faster route has been found. Accept/ Decline' you should be OK to do this, as you would with an in-built sat-nav.
"But if you need to re-programme the route then pull over and stop somewhere safe to do it."
Can you change your music while driving?
"Set up your playlist before you set off.
"Scrolling through songs will be a distraction and if the worst should happen, this would be driving without due care and attention."
Can I decline a call on my phone if it's in a cradle?
"If your phone is connected to your Bluetooth or hands-free system then you should be able to use the button on your steering wheel to decline the call.
"Otherwise, let it ring out or better still, have the phone off and in the glovebox while you're driving so that you can't be tempted or distracted by it."
Can I make calls if I am using voice activation?
"If you use the voice controls and the buttons on your steering wheel this is within the law but for safety, conversations should still be kept to a minimum - for example 'I'm stuck in traffic' or 'I'm running 10 minutes late.'
"This could actually enhance safety by taking the pressure off, so you're not so inclined to rush or speed, but anything much more in-depth than that should be avoided.
Can I read a text when it flashes up on screen in your cradled phone?
"Reading it can still be a distraction and diverts your attention from the road.
"The text will be there when you reach your destination, it can wait.
"When you're driving, your full focus should be on driving."