The European Union's new Entry and Exit System (EES) has encountered another significant issue: the biometric system struggles to differentiate between identical twins. This has led to false accusations of illegal border crossing and travel disruptions for affected individuals.
Identical twin confusion at Romanian border
The problem came to light when a Politico staffer was stopped and questioned by border police in Cluj-Napoca, Romania, in May 2026 while attempting to fly back to the UK. Authorities claimed she had overstayed her permitted time in the Schengen zone because her departure from Amsterdam in April had not been recorded. However, she had not visited Amsterdam that month—her identical twin sister had. Despite explaining the situation, officials accused her of lending her passport to her sister, a claim she denied. She was eventually allowed to board her flight, but the incident raises concerns for identical twins living in the UK.
Scope of the problem
With over 12,000 twins or multiple births in the UK each year, and approximately one-third being identical, a substantial number of British citizens could face similar issues at EU borders. While identical twins are not 100% identical—they have different names, passports, and fingerprints—the EES system appears to rely heavily on facial recognition, leading to errors. A 2012 study in PLoS One found that modern fingerprint verification systems can distinguish identical twins with minimal performance degradation, suggesting the fault lies not in the technology but in its implementation.
Systemic flaws and training gaps
Niovi Vavoula, chair in cyber policy at the University of Luxembourg, attributed the incident to inadequate training and anchoring bias among border officials. She told Politico: “It appears that the authorities are not well trained to distinguish between different processes and rely on facial images as the sole identification method. The fact they didn't check the passport details in the EES, nor take into account that the EES is still fresh and there are various problems, shows what is called anchoring bias—when you rely on the first piece of evidence and disregard everything else.”
EES rollout challenges
The EES, which requires biometric data (photographs and fingerprints) from non-EU citizens at all EU entry points, has faced criticism since its launch in April 2026. Earlier reports highlighted hours-long queues at airports such as Milan's Linate, where travellers fainted and missed flights. Ryanair's chief operations officer, Neal McMahon, described the system as a “half-baked IT system.” The latest issue with identical twins adds to the growing list of operational failures.
Neither Dutch nor Romanian authorities have commented on the specific incident. The EES regulations mandate that authorities should not rely solely on facial recognition but should cross-check fingerprints and passport details, which should differentiate identical twins. However, the incident suggests these procedures are not being followed.
