The EU legal system is unique in the world — it is neither purely international law nor national law, but a new legal order. Understanding its hierarchy, principles, and types of legal acts is essential for every EPSO EU Knowledge question on how EU law works.
1. The Hierarchy of EU Law
EU law is organised in a strict hierarchy. Higher-level norms take precedence over lower-level ones. A legal act that contradicts a higher-level norm can be annulled by the Court of Justice.
Level 1 — Primary Law
Treaties (TEU, TFEU, Charter, Euratom)
The constitution of the EU
▼ takes precedence over
Level 2 — General Principles
Fundamental rights · Proportionality · Legal certainty · Equal treatment
▼ takes precedence over
Level 3 — Secondary Law
Regulations · Directives · Decisions · Recommendations · Opinions (Art. 288 TFEU)
▼ takes precedence over
Level 4 — Supplementary / National Law
Delegated acts · Implementing acts · National law (must comply with all above)
Key principle — Supremacy of EU Law: Established by the Court of Justice in Costa v ENEL (1964): where national law conflicts with EU law, EU law prevails. This is not in the treaties but is a judge-made principle, now widely accepted.
2. Primary Law — The Treaties
Primary law is the highest source of EU law. It consists of:
- Treaty on European Union (TEU) — foundational principles, institutions, external action
- Treaty on the Functioning of the European Union (TFEU) — how the EU works in practice: competences, policies, institutions in detail
- Charter of Fundamental Rights of the EU — legally binding since 2009 (Lisbon), equal to treaty status
- Treaty establishing Euratom — nuclear energy community
- Protocols and Annexes attached to the treaties — have same legal force
Treaties can only be amended by unanimous agreement of all member states, followed by ratification in each country (ordinary revision procedure, Art. 48 TEU).
3. Secondary Law — The Five Types of Legal Acts
Secondary law is created by EU institutions on the basis of treaty provisions. Article 288 TFEU lists five types:
📋
Regulation
Binding in its entirety. Directly applicable in all member states — no national implementing legislation needed. Creates the same law everywhere simultaneously.
Example: GDPR (Regulation 2016/679)
🎯
Directive
Binding as to the result to be achieved, but leaves member states the choice of form and methods. Requires national implementing legislation within a set deadline.
Example: Working Time Directive
📌
Decision
Binding in its entirety on those to whom it is addressed (a member state, company, or individual). Does not require transposition.
Example: Commission competition decisions
💡
Recommendations & Opinions
Not binding. "Soft law" — express a view or suggest a course of action without creating legal obligations. Used to guide or persuade.
Example: Country-specific economic recommendations
| Act | Binding? | Who is bound? | Transposition needed? |
|---|
| Regulation | Yes — fully | All member states + individuals | No — directly applicable |
| Directive | Yes — as to result | Member states | Yes — within deadline |
| Decision | Yes — fully | Addressees only | No |
| Recommendation | No | — | No |
| Opinion | No | — | No |
4. Delegated and Implementing Acts
The Lisbon Treaty introduced a distinction between two types of non-legislative acts:
Delegated Acts (Art. 290 TFEU)
- Commission supplements or amends non-essential elements of a legislative act
- Parliament or Council can revoke the delegation or object to a specific act
- Marked as "delegated regulation/directive/decision"
- Used when technical details need to be updated flexibly
Implementing Acts (Art. 291 TFEU)
- Commission (or Council) adopts uniform conditions for implementing binding acts
- Subject to comitology — oversight by committees of member state experts
- Marked as "implementing regulation/decision"
- Used when uniform application across all member states is needed
5. Key Legal Principles
👑
Supremacy
EU law takes precedence over national law in case of conflict. (Costa v ENEL, 1964)
⚡
Direct Effect
EU law creates rights that individuals can invoke directly before national courts. (Van Gend en Loos, 1963)
🏘️
Subsidiarity
EU acts only where objectives cannot be sufficiently achieved by member states alone. (Art. 5(3) TEU)
⚖️
Proportionality
EU action must not exceed what is necessary to achieve treaty objectives. (Art. 5(4) TEU)
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Legal Certainty
EU law must be clear, precise and predictable. No retroactive effect of penal measures.
🤝
Loyal Cooperation
Member states must take all measures to fulfil EU obligations and not jeopardise EU objectives. (Art. 4(3) TEU)
6. EU Competences
The EU can only act within the powers conferred on it by the treaties (principle of conferral, Art. 5(1) TEU). Competences are divided into three categories:
🔴
Exclusive Competence
Only the EU can legislate. Member states can act only if authorised by the EU.
Examples: customs union, competition rules, monetary policy (eurozone), common commercial policy, conservation of marine biological resources.
Art. 3 TFEU
🟡
Shared Competence
Both EU and member states can legislate. Member states act where the EU has not yet acted (pre-emption).
Examples: internal market, environment, transport, consumer protection, social policy, energy.
Art. 4 TFEU
🟢
Supporting Competence
EU supports, coordinates or supplements member state action. Cannot harmonise national law.
Examples: education, culture, tourism, sport, civil protection, industry.
Art. 6 TFEU
Important — Direct Effect of Directives: Even if a member state fails to transpose a Directive by the deadline, individuals can invoke its provisions directly against the state (but not against other individuals) — the doctrine of direct effect of directives established in Marshall v Southampton (1986).
Key Terms
Primary law
The treaties and the Charter — the highest level of EU law. All secondary acts must conform to primary law.
Directly applicable
An EU act that automatically becomes part of national law without any national implementing legislation (all Regulations are directly applicable).
Direct effect
The ability of EU law to create rights that individuals can rely on before national courts (established by Van Gend en Loos, 1963).
Transposition
The process by which member states incorporate an EU Directive into national law within the specified deadline.
Comitology
The procedure by which the Commission adopts implementing acts with oversight by committees of member state representatives.
Principle of conferral
The EU can only act where the treaties explicitly grant it competence (Art. 5(1) TEU). Everything else remains with member states.