Smiling is prohibited in passport photos for a surprising reason.

Due to the rigorous guidelines for what is permissible, passport images are rarely extremely attractive.

A few rules for a passport to be legitimate include no smiling and keeping hair out of the face.

The UK passport service’s 2005 restriction on smiling in passport photos brought about the latter.

This is because of the passport’s new biometric technology.

The facial recognition software might not recognize the person’s face if they smile.

The BBC was informed by a Home Office spokeswoman that “when the mouth is open, it can make it difficult for facial recognition technology to work effectively.”

On Quora, user Dan Holliday explained why this isn’t possible: “This is because biometric facial scans normally identify 14–20 points on your face (such as the edge of your nose, the corners of your eyes, and your lips), but the position of your face alters those points and may make it difficult to identify who you are.

Because of this, the biometric system functions best if you have a calm, unassuming expression (not frowning or smiling).

On, it is noted that the requirements for passport photos are “in your photo, you must have a neutral expression and your mouth closed.”

Regarding additional security measures for traveler screening, biometric technology is a novel approach.

The UK may soon get access to a revolutionary technology that would reduce passport line wait times to only 15 seconds.

The strategy has already undergone testing in the Netherlands and Australia.

Border controls will need to be strengthened as 123 people enter the UK, as Brexit may cause the number of customs inspections to increase from 90 million to 390 million annually.

95 percent of British and EU nationals currently pass through security in under 25 minutes, but non-EU tourists do so in 45 minutes, putting pressure on airports.

According to Chancellor Philip Hammond, the success of Brexit depends on “frictionless” borders.