More than a decade after the global financial crisis, the Basel III framework is entering its final stage of implementation. These reforms were designed to strengthen the resilience of banks by improving the measurement of risks, increasing capital requirements and limiting excessive variability in the use of internal models, and have become a cornerstone of international financial stability and trust in the banking system. European banks have significantly strengthened their capital position since the crisis, with capital ratios reaching historically high levels and stress tests confirming their capacity to absorb severe shocks.

The finalisation of Basel III nevertheless raises important implementation challenges. In the European Union, the new rules are expected to increase risk-weighted assets and therefore affect banks’ capital requirements, with potential implications for their capacity to finance households and businesses, in an economy where bank lending remains the main source of financing. The impact of the reforms is also expected to vary significantly across institutions, depending on their business models, client base and risk profiles.

A key issue concerns the consistency of implementation across jurisdictions. Differences in the timing, scope and calibration of Basel III rules between major financial centres would affect international competition and create an uneven regulatory landscape for globally active banks, raising concerns about the level playing field and the competitiveness of European institutions.
Developments since 2025 in non-EU jurisdictions have further increased divergences in the implementation of Basel III. In the United Kingdom, the Bank of England has adjusted its approach, lowering certain capital requirements from around 14% to 13%, reflecting an assessment of lower risk in the banking sector and a policy objective to support growth.

In the United States, regulators have also revised their approach to the Basel III “endgame” framework. While the initial 2023 proposal was expected to increase capital requirements for large banks by around 15–20%, recent revisions have significantly reduced the expected impact, with some estimates now pointing to a decrease of own funds of around 5%. Beyond this outcome, the US approach reflects deep structural choices regarding the use of Pillar 2 supervisory add-ons and forward-looking stress tests, and also the scope of the output floor. This architecture is considered by US regulators to offer greater risk-sensitivity and predictability for banks, while preserving supervisory flexibility. For banks this shift reflects concerns about credit provision, market functioning and competitiveness in a context of strong credit demand and economic dynamism.

Against this backdrop, European banks have raised concerns about the implications of a more stringent implementation in the EU. The full implementation of Basel III could increase capital requirements by around 10–15% for some institutions. The European response so far has primarily been to postpone the implementation of certain elements, notably the Fundamental Review of the Trading Book (FRTB), now expected in 2027, alongside ongoing simplification efforts.

The evolving international landscape raises questions about the adequacy of the EU response. In particular, it remains uncertain whether postponements and incremental adjustments will be sufficient, or whether a broader reconsideration of the calibration and architecture of capital requirements may be needed — including a reflection on the respective roles of Pillar 1 standardised rules, Pillar 2 charges and stress testing the specific structure of the European financial system and its reliance on bank financing.