Facial Recognition Tech Dictates the Closed-Mouth Rule for Passport Photos
Biometric algorithms require a neutral expression to accurately measure facial landmarks, a requirement that has evolved since 2004 to match current security standards.
By John Ferrari ·
The United States does not technically ban smiling in passport photographs, yet the requirement for a neutral expression with a closed mouth remains the most common reason for application delays. The State Department mandates that subjects keep their eyes open and mouths closed while looking directly at the camera, a rule driven by the limitations of modern biometric technology rather than aesthetic preference.
The primary driver for this standard is the widespread adoption of facial recognition software at airports and border control checkpoints. Karolina Turowska, a biometric photography expert, explained that algorithms struggle to compare a three-dimensional face with a two-dimensional image when facial proportions shift. A smile alters the distance between key landmarks such as the pupils, ears, nose, and mouth, making it difficult for machines to pinpoint and measure these features accurately.
Katy Nastro, a travel expert, noted that while the rules do not explicitly forbid a smile, they prohibit showing teeth. Pearly whites can obscure eye color and general face shape, which are critical data points for verification. As most ports of entry now rely on computers rather than human officers for initial scans, the need for consistent, measurable facial geometry has become more important for confirming identity.
This neutral expression rule is not unique to the United States. Turowska stated that avoiding smiles is a universal standard for most countries, though specific definitions of neutrality can vary. France, for instance, requires that the corners of the mouth not turn up, even if the mouth is closed. The International Civil Aviation Organization sets these global standards, noting that exaggerated expressions hinder the rapid identification of passport holders.
The current guidelines were updated around 2004 to align with evolving computer capabilities. While the idea for a standardized passport system dates back to 1920, early photographs had few regulations regarding expression. Applicants who submit photos with wide smiles or visible teeth face a processing delay. The State Department will request a new photo, and if the applicant fails to provide an acceptable image by the deadline, the application may remain on hold or be rejected.
Additional strictures apply to accessories and children. Eyeglasses are generally forbidden unless medically necessary, and head coverings are only permitted if part of traditional religious attire. For children, the rules are slightly more lenient because maintaining a neutral expression is challenging. Authorities will accept a smiling photo for a child as long as the subject faces the camera and keeps their eyes open, provided the smile does not impair the recognition of facial features.
