Basel IV, implemented in the EU as the Capital Requirements Regulation 3 (CRR3), is a sweeping overhaul of how banks calculate and report their capital requirements. It tightens the rules around risk-weighted assets, introduces an output floor that limits how much banks can benefit from internal models, and strengthens requirements across credit risk, operational risk, and more. For European banks, CRR3 came into force on 1 January 2025, with a phased transition running through to 2030. The sections below break down exactly what changed, who is most affected, and what banks need to do to stay ahead.

What changes does Basel IV (CRR3) introduce?

Basel IV (CRR3) introduces a fundamental redesign of how banks calculate risk-weighted assets (RWAs), moving away from internal model flexibility toward greater standardization and comparability. The most significant changes are the output floor, a revised standardized approach for credit risk, updated internal ratings-based (IRB) rules, new operational risk requirements, and tighter controls on CVA risk. Together, these changes aim to make capital ratios more consistent and reliable across institutions.

Here is a quick overview of the key changes:

• Output floor: Banks using internal models can no longer calculate RWAs below 72.5% of what the standardized approach would produce.
• Revised standardized approach for credit risk: More risk-sensitive calculations, with updated risk weights for exposures to corporates, retail, real estate, and banks.
• Revised IRB approaches: Restrictions on which exposure types can still use advanced IRB models, and tighter floors on model inputs like LGD and PD.
• Operational risk: A new standardized measurement approach replaces all previous methods, including the Advanced Measurement Approach (AMA).
• Leverage ratio: A new leverage ratio buffer applies to global systemically important institutions (G-SIIs).
• Disclosure: Enhanced Pillar 3 disclosure requirements to improve transparency for investors and supervisors.

The overarching goal is to restore credibility to risk-based capital ratios. Regulators observed that banks using internal models produced RWA estimates that varied widely for similar portfolios, which made capital comparisons across institutions unreliable. CRR3 addresses this by anchoring internal model outputs to a standardized floor.

When do European banks need to comply with CRR3?

European banks are required to comply with CRR3 from 1 January 2025, when the regulation officially entered into force across EU member states. However, full compliance is phased in over a transition period that runs to 1 January 2030, giving banks time to adjust their capital planning, models, and reporting infrastructure.

The output floor is the most significant element being phased in gradually. The floor starts at 50% in 2025 and steps up each year:

1. 2025: 50%
2. 2026: 55%
3. 2027: 60%
4. 2028: 65%
5. 2029: 70%
6. 2030: 72.5% (fully phased in)

This phased approach gives banks a runway to adapt, but it does not mean compliance can be deferred. Banks need to be calculating and reporting under the new standardized approaches from day one, even while the floor is still stepping up. Supervisors expect institutions to demonstrate that they understand their CRR3 capital position well in advance of each annual step-up.

How does the output floor affect bank capital requirements?

The output floor limits the capital benefit banks can gain from using internal models. Under CRR3, a bank’s total RWAs calculated using internal models cannot fall below 72.5% of what the standardized approach would produce for the same portfolio. If a bank’s internal models produce a lower figure, the output floor kicks in and requires the bank to hold more capital.

In practice, this means banks that have historically used sophisticated internal models to achieve low RWAs will see their capital requirements increase. The degree of impact depends on how far below the 72.5% threshold their internal model outputs currently are.

For banks with large, well-diversified mortgage portfolios or low-risk corporate lending books, internal models have often produced RWAs significantly below the standardized approach. Under the output floor, that gap is now capped. This translates directly into higher minimum capital requirements for those institutions.

It is worth noting that the output floor applies at the consolidated group level, not on a portfolio-by-portfolio basis. This means a bank can still benefit from diversification across its portfolio, but the total RWA figure cannot drop below the 72.5% threshold of the standardized equivalent.

Which European banks are most affected by Basel IV?

The European banks most affected by Basel IV are large institutions that rely heavily on advanced internal models, particularly those with significant mortgage books, low-risk corporate portfolios, or complex financial instrument exposures. These banks have historically benefited most from internal model flexibility, so the output floor hits them hardest.

Several patterns emerge when looking at which institutions face the greatest capital impact:

• Large universal banks with mortgage-heavy portfolios: Banks in markets like the Netherlands, Denmark, and Sweden have historically assigned very low risk weights to residential mortgages using internal models. The revised standardized approach assigns higher risk weights to these exposures, pushing up the floor calculation.
• Banks with extensive IRB model coverage: Institutions that have invested heavily in advanced IRB models across many asset classes will find that more of their portfolio is now subject to floor constraints.
• G-SIIs and other large cross-border banks: These banks face not only the output floor but also the new leverage ratio buffer, amplifying the overall capital impact.

Smaller banks that already use the standardized approach for most of their calculations will see less disruption, since the output floor is less likely to bind when internal models are not in play. For these institutions, the main challenge is adapting to the revised standardized approach risk weights rather than the floor itself.

What does Basel IV mean for credit pricing and lending?

Basel IV is likely to push up the cost of credit for certain borrower types, particularly where the new rules increase risk weights and therefore the capital a bank must hold against a loan. When capital requirements rise, banks need to earn a higher return on that capital to stay profitable, which typically flows through to borrowers in the form of higher loan pricing.

The most noticeable effects are expected in a few specific areas:

• Residential mortgages: In markets where banks currently use very low internal model risk weights for mortgages, higher standardized floor calculations could make mortgage lending more expensive.
• Unrated corporate lending: The revised standardized approach introduces differentiated risk weights for rated and unrated corporates. Lending to unrated companies, which is common in many European markets, may attract higher risk weights than before.
• Specialized lending: Project finance, object finance, and commodities finance face updated risk weight treatments that could affect pricing in those segments.

That said, the overall lending impact will vary significantly by bank and market. Banks with strong capital positions may absorb some of the additional requirement without passing the full cost on to borrowers. Competitive dynamics in local lending markets will also play a role in how much of any capital cost increase actually reaches borrowers.

How can banks prepare their risk infrastructure for CRR3?

Preparing for CRR3 requires banks to upgrade both their calculation capabilities and their data infrastructure. The regulation demands more granular, standardized calculations across credit risk, operational risk, and leverage, which means legacy batch-processing systems that produce results overnight are no longer fit for purpose. Banks need systems that can run the standardized approach alongside internal models, calculate the output floor in real time, and support ongoing stress testing and ICAAP requirements.

The most useful steps banks can take right now are:

1. Run a gap analysis: Map your current RWA calculations against CRR3 standardized approach requirements to identify where the output floor is likely to bind and by how much.
2. Upgrade data management: CRR3 requires more detailed, accurate data at the contract level. Aligning your data infrastructure with BCBS 239 principles for data aggregation and reporting is a practical starting point.
3. Integrate standardized and internal model calculations: Your risk platform needs to run both approaches simultaneously and compare them automatically, not as a manual exercise.
4. Strengthen your ICAAP stress testing: Regulators expect banks to demonstrate that their capital planning accounts for CRR3 impacts under a range of economic scenarios. A robust ICAAP stress test framework, integrated with your balance sheet and credit risk models, is central to this.
5. Plan for Pillar 3 disclosure: Enhanced disclosure requirements mean more granular, auditable reporting. Building data lineage from source systems through to regulatory outputs will save significant effort at submission time.

At ElysianNxt, our Basel.NXT module was built specifically to handle the full Basel IV framework, covering credit risk under both the revised standardized and IRB approaches, output floor calculations, liquidity ratios, leverage ratio, and ICAAP and ILAAP support, all within a single platform. Banks that have already implemented IFRS 9 with us have found it straightforward to extend the platform to cover Basel III and Basel IV, centralizing all credit risk data in one place and running regulatory calculations in minutes rather than hours. If your current infrastructure is not ready for the 2026 output floor step-up, now is the right time to act.