It is possible to be turned away from a film rated 15-18 because you do not have the proper identification.
The UK Cinema Association, which includes Cineworld and Showcase Cinemas as well as Vue, has partnered with Yoti, a digital ID firm.
This app is free and will be accepted as proof that you are at least 18 years old. It also allows you to easily show your ID.
It is hoped that the move will also address abuse of cinema staff.
Yoti uses the same technology as at the airport where you scan your passport to capture a picture of you.
Children will need a smartphone to download the Yoti ID app. They can add details from their passports and take a photo.
The digital ID card will show an age-verified picture which can be accepted by cinema staff.
Phil Clapp, the CEO of the UK Cinema Association, stated that 30% to 30% of the admissions in UK cinemas each year were within the 15-24 age bracket, and 20% to the 9-14 age group.
"It can be difficult for many to prove their age without a passport or driving license. This is why it can be frustrating for them if they are turned away from the cinema.
Yoti's apps are downloaded over 11 million times worldwide and have been accepted by many organisations, including Virgin Atlantic, the NHS and the NSPCC.
Robin Tombs is the CEO and Co-founder of Yoti. He said, "We're thrilled that many UK Cinema Association members have joined the 30,000 locations in the UK high streets accepting our reusable digital identification apps."
"Young people expect their phones to do everything, and they will be able use it to prove their age. Both cinemas and young moviegoers will benefit.
It is hoped that the digital ID will reduce the pressure on staff to carry out age checks.
Shaun Jones, Cineworld's vice-president for operations, stated to the BBC that abuse against staff occurs more often than you might imagine. It comes from young people but also from parents.
"When asked about young people's identification, parents are frustrated and angry at being asked for their children’s passports. They refuse to allow them to take it out of their home.
"We expect the digital ID technology Yoti will really help eliminate some of the abuse to employees."