When a bank considers financing a business expansion, a commercial property purchase or a home mortgage, it evaluates more than the borrower’s ability to repay. It must also consider how much regulatory capital the loan requires and how that exposure affects the bank’s financial position.
These calculations are central to Basel III capital rules, the international standards developed after the 2008 financial crisis to strengthen banks’ ability to absorb losses. In 2026, those standards remain important, but their implementation is evolving differently across jurisdictions.
In the United States, regulators have proposed a revised capital framework that could change how large banks and other lenders calculate risk, particularly for mortgages, business loans and trading activities. The proposals seek to align capital requirements more closely with risk while reducing overlapping calculations.
For borrowers, the outcome matters because capital requirements can influence which loans banks prefer to make, how they price credit and how much financing they are willing to provide. However, capital regulation is only one influence on lending; interest rates, deposit costs, competition and economic conditions matter too.
What Basel III Requires
Basel III is a set of international banking standards developed by the Basel Committee on Banking Supervision in response to weaknesses exposed by the global financial crisis. Its objectives include improving capital quality, strengthening loss-absorbing capacity and making banks more resilient during periods of financial stress.
Three concepts help explain how the framework works.
Regulatory capital is the financial cushion banks must maintain against losses. Common Equity Tier 1 (CET1), which primarily consists of common shares and retained earnings, is a particularly important measure because it represents high-quality capital available to absorb losses.
Risk-weighted assets (RWA) adjust a bank’s exposures according to their regulatory risk weights. A loan considered riskier may contribute more to RWA than a lower-risk exposure of the same size.
Capital ratios compare a bank’s qualifying capital with its risk-weighted assets. If a bank has $10 billion in CET1 capital and $100 billion in RWA, its CET1 ratio is 10%.
Suppose a $10 million loan adds $10 million to RWA. At a hypothetical 10% CET1 target, the bank would need $1 million of CET1 capital to support that exposure. If the loan instead added $5 million to RWA, the corresponding amount would be $500,000. These figures are illustrative, not universal regulatory requirements.
The actual calculation depends on the bank’s applicable rules, risk classification, capital buffers and other requirements. Basel III also includes measures such as leverage requirements and additional buffers for systemically important banks.
The international standards do not automatically become identical domestic law everywhere. National regulators determine how the framework applies to their banking systems, including scope, calibration and implementation timelines.
What Is Changing in 2026?
The central U.S. development is a set of proposed reforms published on March 19, 2026, by the Federal Reserve, the Federal Deposit Insurance Corporation and the Office of the Comptroller of the Currency.
The proposals cover three related areas:
- A revised risk-based capital framework for the largest, most internationally active banks and institutions with significant trading activity.
- Changes to the standardized capital approach used by other banking organizations.
- A revised method for calculating the additional capital surcharge imposed on global systemically important banks, or G-SIBs.
For large banks covered by the proposed expanded risk-based approach, regulators would replace the existing dual calculation method with a single framework for risk-based capital ratios. Other banks would generally retain the option to adopt the expanded approach.
The standardized-approach proposal would recalibrate selected risk weights and modify the treatment of certain exposures, including mortgage servicing assets. The G-SIB proposal would revise how systemic importance is measured when determining additional capital requirements.
The agencies said the proposed changes would modestly reduce aggregate capital requirements while retaining substantial safeguards. Supporters argue that better calibration could reduce incentives to move traditional lending outside regulated banks. Critics caution that reducing capital requirements could leave less protection against unexpected losses.
Important 2026 update: The comment period for these capital proposals closed on June 18. As of October 23, the official records still list the core Basel III and standardized-approach measures as proposed rules. They should not be described as a fully finalized new capital regime. Separately, on September 30, the Federal Reserve finalized changes to stress-test transparency and the calculation of stress capital buffers. Those are distinct measures, not final adoption of the March Basel III proposals. The Federal Reserve’s 2026 capital-rule proposals and regulatory updates provide the relevant official background.
Internationally, implementation is also uneven. The Basel Committee’s implementation dashboard and September 2026 progress update reported that adoption of the final Basel III standards continued across jurisdictions, with implementation expected to be nearly complete by the first half of 2027. National differences mean borrowers should not assume that U.S. changes apply to lenders in Europe, the United Kingdom or other markets.
How Capital Rules Affect Lending
Capital requirements influence lending through the cost and availability of a bank’s balance-sheet capacity.
A bank that must allocate more capital to a loan may seek a higher interest margin, charge additional fees, request stronger collateral or favor a different borrower. Alternatively, it may decide that the expected return does not justify the capital required and decline the transaction.
This does not mean every increase in capital requirements leads directly to higher borrowing costs. Banks can absorb some costs through lower returns to shareholders, operating efficiencies or changes to other parts of their portfolios. Competition can also limit their ability to pass costs on to customers.
Risk weights matter because different loans can consume different amounts of regulatory capital. A well-secured loan to a financially strong borrower may receive more favorable treatment than a riskier exposure, depending on the applicable framework. If proposed rules make those differences more accurately reflect risk, some forms of lending could become relatively more attractive to banks.
The opposite concern is that poorly calibrated rules may discourage economically useful lending or push activity toward less-regulated providers. Regulators therefore face a trade-off: capital must be sufficient to absorb losses without unnecessarily constraining credit.
Impact on Mortgages, Commercial Real Estate and Business Loans
Mortgage lending
Mortgage capital treatment can influence both loan origination and servicing. Servicing involves administering a mortgage after it has been issued, including collecting payments and managing related records.
The 2026 standardized-approach proposal would modify the treatment of mortgage servicing assets and recalibrate selected lending exposures. If adopted as proposed, these changes could reduce some capital-related disincentives for banks to originate or service mortgages.
That would not automatically translate into lower mortgage rates. Funding costs, borrower creditworthiness, competition, housing demand and broader interest-rate conditions would continue to influence pricing.
Commercial real estate
Commercial real estate lending depends on property income, occupancy, collateral values, debt-service coverage and borrower finances. Capital rules influence how banks assess and hold these exposures, but they are not the only determinant of lending decisions.
When property values weaken or refinancing risks rise, lenders may tighten underwriting regardless of changes to capital rules. Conversely, more risk-sensitive capital treatment could affect the relative attractiveness of different property loans.
For investors evaluating financing options, these issues overlap with the wider institutional investment shift toward critical infrastructure assets, where financing requirements and project risk can vary considerably.
Small businesses and corporate borrowers
Small businesses often depend on banks for working capital, equipment financing and expansion loans. Large corporations may have additional options, including bond issuance, syndicated loans and private credit.
Changes to capital treatment could affect banks’ willingness to lend to different business categories. But credit availability will also depend on cash flow, collateral, business outlook and the lender’s appetite for risk.
If a bank faces tighter capital constraints, it may reduce lending, adjust pricing or shift toward other assets. If proposed changes lower the capital cost of a particular exposure, the bank may have more room to compete. Neither outcome is guaranteed for every borrower.
Large Banks, Smaller Banks and Nonbank Lenders
Large, internationally active banks face more complex capital frameworks because of their scale, trading activity and potential impact on the financial system. They may also have greater access to capital markets and more resources to manage regulatory compliance.
Smaller banks generally operate under a more standardized framework, although their requirements vary by size, business model and regulatory category. The 2026 U.S. proposals would recalibrate parts of the standardized approach and give eligible institutions options regarding the expanded framework.
Nonbank lenders including specialist mortgage companies and private credit funds do not all face the same bank capital rules. Their regulatory obligations depend on their structure, activities and jurisdiction. This can create differences in how they price and distribute credit.
However, nonbanks still face their own funding, liquidity, investor and risk-management constraints. Moving lending outside the banking sector does not eliminate risk; it can change where that risk sits and how visible it is to regulators.
The growth of private credit illustrates this broader shift. Borrowers comparing bank loans with private credit financing and its role in alternative lending should compare total borrowing costs, covenants, flexibility, collateral requirements and refinancing risks rather than assuming one source is always cheaper.
What Borrowers and Investors Should Watch
Three developments deserve attention through the remainder of 2026 and into 2027.
First, watch for final U.S. rules and their implementation schedules. A proposal can change following public comments, technical revisions and regulatory review. Banks may prepare for potential changes before they take effect, but borrowers should not treat proposed capital relief as a guaranteed improvement in loan availability.
Second, monitor lending standards and actual credit conditions. Bank surveys, lending data, mortgage pricing and business-credit availability can help show whether financing is becoming easier or more restrictive. Capital requirements should be considered alongside funding costs, economic growth and borrower demand.
Third, watch how banks allocate capital across loan types and how nonbank lenders respond. Changes in relative costs may influence competition, but the effects will vary by borrower, product and market.
For businesses planning investment or refinancing, it is prudent to maintain realistic financing assumptions and consider more than one funding source where appropriate. For households, mortgage affordability still depends on income, debt obligations, down payments and prevailing rates not regulatory changes alone.
Conclusion
Basel III capital rules remain central to how banks measure risk, protect themselves against losses and decide how to allocate lending capacity. In 2026, U.S. regulators are proposing a revised framework intended to simplify calculations and align capital requirements more closely with risk, while preserving financial resilience.
The outcome will depend on the final rules, their timing and how banks respond. Some lending activities could become more attractive to regulated institutions, but borrowers should not assume that capital relief will automatically produce cheaper or more readily available credit.
The essential point is that Basel III capital rules influence the economics of lending, not lending decisions in isolation. Interest rates, funding costs, competition, borrower quality and economic conditions remain equally important to understanding who gets credit, at what price and on what terms.
Disclaimer: This article is for informational purposes only and does not constitute individualized financial, legal, investment or lending advice.
Ana Goldenberg is a Contributing Editor at Alt Finances with a career rooted in the high-stakes worlds of banking and private placements. From profiling global philanthropists to managing complex financial operations at Wells Fargo, she bridges the gap between editorial storytelling and disciplined financial expertise.
