Short answer
A national product rule is normally a measure having equivalent effect to a quantitative restriction under Article 34 of the Treaty on the Functioning of the European Union (TFEU) if it can hinder imports between Member States. That includes destination-state requirements on composition, dimensions, naming, packaging, labelling, testing, or presentation, even if they formally apply to all goods alike.
For goods lawfully marketed in another Member State, mutual recognition means that different national technical rules are not, by themselves, a sufficient reason to deny market access. The destination state may still apply a restriction if it proves a permitted public-interest objective and shows that the measure is suitable and no more restrictive than necessary. Article 36 TFEU supplies express grounds. The case law also recognises “mandatory requirements” for certain indistinctly applicable rules in non-harmonised areas. The analysis therefore moves through harmonisation, hindrance or market access, mutual recognition, justification, and proportionality—not simply whether the rule mentions imports.
Start with Article 34 TFEU
Article 34 is broader than a ban on quotas. Its current wording is short:
Quantitative restrictions on imports and all measures having equivalent effect shall be prohibited between Member States. —
The rule concerns measures attributable to a Member State and trade between Member States. Identify the product, national requirement, cross-border facts, and practical obstacle.
First ask whether EU legislation has exhaustively harmonised the product characteristic. If so, that EU act supplies the primary test. Article 34 does not replace the specific harmonised standard. Mutual recognition matters chiefly for goods, or aspects of goods, not exhaustively harmonised.
Case C-604/24 illustrates that sequence. On 21 May 2026 the Court applied Article 85c of Directive 2001/83/EC and held that it precluded a national online-sales prohibition covering most non-prescription medicines. The operative answer came from the harmonising directive, demonstrating why applicable secondary legislation must be identified before direct Treaty analysis.
Product requirements usually fall within the prohibition
The Court of Justice's starting point in Dassonville, Case 8/74, was deliberately broad:
All trading rules enacted by Member States which are capable of hindering, directly or indirectly, actually or potentially, intra-Community trade are to be considered as measures having an effect equivalent to quantitative restrictions. —
A rule need not impose a numerical limit or target foreign goods. Direct discrimination is an obvious case. A neutral technical rule may also obstruct trade by requiring alteration of a product made under another Member State's rules.
Product requirements include rules on designation, form, size, weight, composition, presentation, labelling, packaging, or testing. Applying them equally does not remove the additional burden on goods made under another lawful standard.
Mutual recognition changes the starting assumption
In Cassis de Dijon, Case 120/78, Germany applied a minimum alcohol-content rule to a fruit liqueur lawfully sold in France. The Court rejected the restriction and articulated the foundation of mutual recognition:
There is therefore no valid reason why, provided that they have been lawfully produced and marketed in one of the Member States, alcoholic beverages should not be introduced into any other Member State; the sale of such products may not be subject to a legal prohibition on the marketing of beverages with an alcohol content lower than the limit set by the national rules. —
Mutual recognition does not require every Member State to adopt the least demanding standard. It requires the authority to assess whether imported goods already protect the relevant interest adequately, even by different means.
Regulation (EU) 2019/515 now adds a procedural framework for goods lawfully marketed in another Member State where national technical rules apply. It covers non-harmonised goods and non-harmonised aspects of partly harmonised goods:
This Regulation lays down rules and procedures concerning the application by Member States of the principle of mutual recognition in individual cases in relation to goods which are subject to Article 34 TFEU and which are lawfully marketed in another Member State, having regard to Article 36 TFEU and the case-law of the Court of Justice of the European Union. —
An economic operator may use the Regulation's voluntary mutual-recognition declaration to demonstrate lawful marketing. If an authority restricts or denies access after assessment, Article 5 requires a detailed decision identifying the national rule, public-interest ground, evidence, operator's relevant arguments, proportionality assessment, and remedies. The Regulation does not create an automatic right to sell unsafe goods or displace harmonised EU requirements.
Selling arrangements and use rules require closer analysis
Not every national rule affecting sales is a product requirement. In Keck and Mithouard, Joined Cases C-267/91 and C-268/91, the Court distinguished certain “selling arrangements”. A rule governing how, when, or where goods are sold can fall outside Article 34 if it applies to all relevant traders in the territory and affects domestic and imported goods in the same manner both in law and in fact.
That exception is conditional: a neutral advertising, online-sales, pricing, or distribution rule may still disadvantage imports in fact. Product-characteristic rules remain product requirements.
The Court's later judgment in Commission v Italy (Trailers), Case C-110/05, placed market access at the centre. Product requirements, less favourable treatment of imports, and other measures hindering imported products' access to a national market can all fall within Article 34. A use restriction may therefore be caught. Italy's prohibition made consumers practically uninterested in buying trailers designed for motorcycles, suppressing demand and hindering imports even though the rule addressed use rather than manufacture.
The practical question is whether the rule requires alteration, treats imports less favourably, limits normal use, suppresses demand, or otherwise makes market entry materially harder.
Article 36 and mandatory requirements are routes to justification
A measure within Article 34 is not necessarily unlawful. Article 36 permits restrictions justified by public morality, public policy, public security, protection of human, animal, or plant health and life, protection of national treasures, or protection of industrial and commercial property. Its final sentence bars arbitrary discrimination and disguised restrictions on trade.
In non-harmonised areas, Cassis de Dijon also recognised mandatory requirements, now often described as overriding reasons in the public interest. Its examples were effective fiscal supervision, public health, fairness of commercial transactions, and consumer protection. This judicial route ordinarily concerns rules applying without distinction; a directly discriminatory measure cannot generally be rescued simply by invoking an open-ended mandatory requirement.
The Member State must identify the real objective and connect the measure to it with evidence. It cannot use a general public-interest argument to reopen exhaustive EU harmonisation unless the EU measure permits it.
Proportionality decides whether the restriction survives
The restriction must be suitable for achieving the stated objective and must not go beyond what is necessary. A less restrictive measure that protects the interest as effectively can defeat the national rule. In Cassis, suitable origin and alcohol-content labelling was a less restrictive response than excluding lower-strength liqueurs. In Scotch Whisky Association, Case C-333/14, the Court required an objective examination of the evidence and of whether less trade-restrictive means could achieve the health objective.
A Member State need not disprove every conceivable alternative, but it must substantiate necessity and address plausible options such as warnings, labelling, targeted checks, equivalent testing, or a narrower restriction.
A practical assessment checklist
- Identify harmonisation. Does an EU act exhaustively regulate the relevant product characteristic, approval, or risk?
- Confirm the cross-border facts. Is the product imported or lawfully marketed in another Member State, and what national authority or rule creates the obstacle?
- Classify the rule. Is it discriminatory, a product requirement, a selling arrangement, a use restriction, or another market-access obstacle?
- Measure the practical effect. Must the product be changed, retested, relabelled, withheld, or deprived of normal demand?
- Apply mutual recognition. Has the authority assessed the protection already achieved in the Member State of lawful marketing?
- Test the justification. Is the objective within Article 36 or a recognised mandatory requirement available for this kind of rule?
- Test evidence and proportionality. Is the measure suitable, consistent, and necessary, and could a less restrictive measure protect the interest as effectively?
- Check procedure. Where Regulation 2019/515 applies, did the authority follow its assessment, reasoning, notification, and remedy requirements?
Conclusion
A national product rule is a measure equivalent to a quantitative restriction when it is capable of hindering trade between Member States, particularly by forcing lawfully marketed imports to satisfy a second set of product specifications or by materially obstructing market access. Formal equality between domestic and imported goods is not enough.
Mutual recognition makes lawful marketing in another Member State the starting point, not the end. A destination state may invoke Article 36 or, where available, mandatory requirements, but must justify the restriction with evidence and proportionality. The decisive question is whether a less trade-restrictive measure would protect the public interest as effectively.
Sources
This article provides general legal information, not advice for a specific matter. Laws, facts and procedural deadlines may change the result. Follow the linked primary sources and obtain local advice before acting.