Singapore's Changi Airport is among the first to ditch the need for passports in favour of automated biometric checks using cameras - with governments around the world reportedly looking to make a similar change.
Instead of presenting a passport, travellers simply step up to a camera kiosk in Changi Airport to verify their identity using a facial recognition camera - with people's faces used as ID at different touch points including bag drop and boarding.
The move is happening in parallel with a move away from traditional paper passports and towards digital documents stored on smartphones.
Which airports offer passport-free travel?
As well as Changi, Dubai International Airport is also replacing passport checks with biometric clearance.
Passengers can walk through the terminal and onto planes using only their face as ID. The system was first introduced for UAE citizens, but it is being widened for international travellers.
Airports around the world are also trialling similar schemes, with some places like Hong Kong International Airport, Tokyo Narita, Tokyo Haneda, Indira Gandhi International in Delhi and Paris Charles de Gaulle already using facial recognition technology.
What about Britain?
The UK has looked at introducing similar schemes with, Phil Douglas, the director-general of Border Force, previously explaining his plans for an "intelligent border" with facial recognition technology and no need to physically present passports.
The government began a trial on facial recognition e-gates at the start of 2024, with a view to making entering the UK "frictionless".
Douglas told The Times in January that he was inspired by a recent trip to Australia. He said: "I had to apply for an electronic travel authorisation in advance and used my smartphone to read the chip in my passport.
"That sent the image of me in the chip to the Australian authorities. When I arrived in Australia, I didn't even have to get my passport out of my bag. It is a really interesting concept."
He predicted the use of a standard passport desk would "fall away" in the UK in the next two to three years.
Britain is already rolling out electronic travel authorisation (ETA) for foreign arrivals coming to the UK who do not need a visa. Currently, only a few countries can use the system, but the government plans to introduce it to all nationalities who do not need a visa - integrating it with EU visitors is a big target.
For £10, passengers won't need to go through passport checks. Instead, travellers are required to download an app, answer a set of questions, scan their passport and provide a photo, with only those granted the ETA able to board flights into the UK.
What about digital passports?
Research by the International Air Transport Association (IATA) global passenger survey found that more than 90% of young people would be open to digital passports.
Countries such as Finland have already introduced the documents, and the EU is planning to introduce digital documents for 'faster, smoother' travel by 2030.
The British government's Department for Digital, Culture, Media and Sport is investigating different digital identity documents, with the hope of making digital documents 'as trusted as passports'.
Are there any concerns with the new systems?
Yes, these fall into two categories: what happens when the network fails and privacy concerns.
Campaigners have raised issues with the dystopian-sounding technology, with cameras able to verify a person's identity by using data stored on a database. Although the cameras will be pointed out to customers at first, in the future they may well be hidden and people will be unaware their identity is being checked.
The topic of people having rights to their biometric data is being debated by parliaments across the world, with the chair of the European Data Protection Board Anu Talus warning against its abuse in May.
She said: "Facial recognition technology can lead to false negatives, bias and discrimination. Misuse of biometric data can also have grave consequences, such as identity fraud or impersonation.
"Therefore, we urge airline companies and airport operators to opt for less intrusive ways to streamline passenger flows, when possible. In the view of the EDPB, individuals should have maximum control over their own biometric data."
In the US, the Transport Security Administration was criticised by a group of senators when they trialled facial recognition in airports. They said: "Increasing biometric surveillance of Americans by the government represents a risk to civil liberties and privacy rights."
There is also the problem of what to do when the technology fails. E-gates are already in use in British airports for UK nationals, but they caused chaos last May when they went offline just before the start of the school holidays, causing delays for thousands of travellers.