One problem that is gaining more and more prominence is gold-plating: when Member States introduce a wider scope or more burdensome procedures on top of the harmonised baseline an EU act requires.

These additions are not necessarily unlawful, and legitimate national discretion of course sometimes makes sense. In fact, for companies, the problem is rarely one national addition on its own. It is instead the patchwork of repeated compliance processes that emerges when companies must accommodate different requirements across the EU.

Take the General Data Protection Regulation. Despite being a directly applicable regulation, national measures have created different requirements around data protection officers, employee data, digital consent and sanctions. Identical processing can therefore carry different obligations and risks depending on the country.

For companies, that means no genuinely group-wide governance model, no uniform HR policy and country-specific assessments for the same activity.

The Packaging and Packaging Waste Regulation tells a similar story. National labelling codes, documentation requirements, reuse systems and recycling targets can coexist with, or go beyond, the harmonised framework. Country-specific packaging and markings prevent a standard European solution, fragmenting production and logistics.

The Single Market promises scale. These national additions take it away.

Member States should therefore start from the position that gold-plating is a last resort. Any departure from the harmonised EU framework should face a high bar, with governments required to demonstrate that the benefits clearly outweigh the resulting burden. Common definitions, templates and methodologies should be the default wherever divergence creates cross-border complexity.

This discipline must also be preventative. The Public Procurement Act, for example, is a live file where Member States will need to be disciplined to avoid divergent transposition. Guidance is needed before 27 systems become embedded, not after companies have built processes around them.

Some of the Single Market’s biggest barriers run deeper still, rooted in legal systems that remain distinctly national. These barriers impede scale.

Capital markets are a prime example. Financial activity is increasingly cross-border, but supervision and infrastructure remain fragmented. Operators may need separate structures and supervisory relationships in different Member States, while differences in national insolvency law create further uncertainty for investors.

These barriers increase costs and make it harder for European savings to reach promising companies and projects. Europe cannot build deeper capital markets while key parts of its financial architecture remain organised around national borders.

Workers face barriers too. As the Financial Times points out, a master baker – fully qualified in France, for example – will find their qualifications not recognised in Germany. Licensing rules, recognition procedures and pension-portability hurdles continue to make movement between Member States more difficult than they should be in a Single Market.

Full harmonisation will not always be possible. But Member States can apply mutual recognition more consistently, simplify recognition procedures and reassess restrictions that unnecessarily impede mobility. The test should be whether a national requirement is genuinely necessary, not merely whether it has always existed.