The EU's "single" border system has become five

The EU's Entry/Exit System (EES) was sold as the end of the messy patchwork of European border checks: one biometric system, applied uniformly across the Schengen zone, replacing decades of inconsistent stamping and scanning. Nine months on from full rollout, it has done the opposite. Rather than one border, travellers now face five.

The first is the system as designed. On paper, every Schengen country is meant to apply full biometric checks to every arriving traveller. A small number of countries are still attempting this in practice.

The second is the system as permitted. Brussels has granted nine countries, France, Germany, Italy, Greece, Portugal, Belgium, the Netherlands, Switzerland and Malta, an exemption allowing them to apply the checks flexibly so queues keep moving. For most travellers passing through Europe's busiest hubs, this is the border they'll actually encounter.

The third exists outside Schengen altogether. Ireland and Cyprus don't implement EES checks at all. Given the practical realities of the Irish border, Ireland may never be able to.

The fourth is a national exception layered on top of a regional one. Greece has separately declared that British holidaymakers won't face biometric checks until further notice, regardless of what the wider nine-country exemption allows.

The fifth is mechanical rather than political. At Dover and Folkestone, non-functioning EES machines mean travellers can simply drive past them and onto a ferry, checks or no checks.

The result is a system that promised harmonisation and delivered fragmentation: a single rulebook interpreted, exempted and ignored in five distinct ways depending on where, and sometimes who, you are. For a project meant to simplify Europe's borders, EES has instead become a case study in how quickly a unified policy can splinter once it meets the reality of enforcement.