What varies by member state
The Act is a single EU regulation, so the core rules are the same everywhere. But some of how it is run, and a few of the choices it allows, sit with each member state.
The core is harmonised
The risk tiers, the prohibited practices, the deployer duties, and the deadlines are all set at EU level and apply across every member state. A high-risk use is high-risk whether you operate in Dublin or Lisbon.
As a regulation rather than a directive, the Act applies directly, without each country writing its own version. For anyone operating across borders that is good news: the substance is the same everywhere.
Each country names its authorities
Member states designate the national bodies that supervise and enforce the Act, including at least one market surveillance authority. Which body you would actually deal with depends on where you are established and operate.
Some countries route AI Act oversight through an existing regulator, such as a data protection or product-safety authority; others stand up something dedicated. Knowing your national authority is part of being ready.
Some choices are national
A few areas are left to national law and can differ between countries, most notably the narrow conditions around certain biometric uses by law enforcement. These are the exception, not the rule, and rarely touch an ordinary business.
Penalties are also set by each member state within the ceilings the Act fixes, so the maximum is harmonised even where the detail of enforcement is local.
Language and process
Notices, documentation, and dealings with authorities may need to be in the local language, and the procedural detail of how an authority engages can vary from one country to the next.
For a business operating in a single country this is straightforward. For one operating in several, it is worth knowing which language and which authority apply where.
If you operate in several countries
The substance of your obligations travels with you, so you do not have to redo your classification or your documents country by country. What changes is which national authority you answer to and any local specifics.
At EU level, the AI Office and the European Artificial Intelligence Board work to keep enforcement consistent across borders, so the aim is one set of rules applied evenly, not a patchwork.
This guide is general educational information, not legal advice. For how the Act applies to your organisation, classify your systems and consult qualified counsel.
Put it into practice
Classify your AI systems against the Act and generate the documents this guide describes.