The EU's new Entry and Exit System (EES) has encountered another issue: it struggles to distinguish between identical twins. The system, which relies on biometric data such as fingerprints and photographs, has been causing chaos at EU borders since its rollout in April 2026.
Identical Twin Incident in Romania
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 accused her of being illegally in the Schengen zone because her departure from Amsterdam in April had not been recorded. However, she had not been to Amsterdam that month—her identical twin sister had.
Despite explaining the situation, officials accused her of lending her passport to her sister, which she denied. Her twin was in the UK at the time and had never visited Romania. Ultimately, she was allowed to board her flight, but the incident raises concerns for other identical twins.
Scale of the Problem
With over 12,000 twin or multiple births in the UK each year, and approximately one-third being identical, many Britons could face similar issues. Although identical twins share many features, they have different names, passports, and fingerprints. A 2012 study in PLoS One found that automatic fingerprint verification systems can distinguish identical twins without significant performance degradation. EES regulations also require authorities to use multiple identification methods, not just facial recognition.
What Went Wrong?
Niovi Vavoula, chair in cyber policy at the University of Luxembourg, 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.' She added, '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.'
Thus, the issue likely stems from how EES checks were conducted when the woman entered Romania and her twin left Amsterdam, rather than the fingerprint system itself. Neither Dutch nor Romanian authorities have commented on the incident.
