Regulatory capital is the amount of capital that a licensed financial institution is required by law to hold, calculated according to rules set by its regulator. It is meant to absorb losses so that the firm can keep meeting its obligations to depositors, customers and counterparties if things go wrong. Regulatory capital differs from ordinary accounting equity: regulators decide which items count, which must be deducted, and what the firm's capital must be measured against, such as risk-weighted assets for a bank or payment volume for a payment institution.
Holding the required capital is a continuing condition of a license, not a one-time hurdle. A firm must show it at application, report it regularly, and maintain it at every examination; falling below the minimum can lead to restrictions, a capital plan imposed by the regulator, or loss of the license.
Regulatory capital for banks
For banks, the international reference is the framework of the Basel Committee on Banking Supervision, hosted by the Bank for International Settlements. The first Basel Accord in 1988 set a minimum ratio of capital to risk-weighted assets of 8%. Basel II (2004) refined how risk weights were calculated, and Basel III, agreed in 2010 after the 2008 financial crisis, raised both the quantity and the quality of capital.
Under Basel III, capital is divided into tiers:
- Common Equity Tier 1 (CET1): mainly ordinary shares and retained earnings, after deductions such as goodwill and certain deferred tax assets. The minimum is 4.5% of risk-weighted assets.
- Additional Tier 1: perpetual instruments that can absorb losses while the bank is a going concern. Tier 1 capital in total must be at least 6%.
- Tier 2: subordinated debt and certain provisions that absorb losses when a bank fails. Total capital must be at least 8%.
On top of these minimums, banks must hold a capital conservation buffer of 2.5% of CET1, and may face a countercyclical buffer and extra surcharges if they are systemically important. Basel III also added a leverage ratio and liquidity standards. National supervisors, such as the Prudential Regulation Authority in the UK, implement these standards and can require more.
Regulatory capital for payment and e-money firms
Non-bank payment firms are subject to simpler regimes. In the European Union, PSD2 sets initial capital for payment institutions at EUR 20,000 for money remittance, EUR 50,000 for payment initiation services and EUR 125,000 for other payment services, with ongoing own funds calculated by one of three methods linked to fixed overheads, payment volume or a scaled indicator. An electronic money institution needs EUR 350,000 of initial capital and ongoing own funds of at least 2% of average outstanding e-money. The UK applies the same structure under its own regulations.
Net worth for US money transmitters
US state money transmission laws generally express the requirement as a minimum net worth, often tangible net worth, which excludes intangible assets such as goodwill. Amounts vary by state and often rise with the licensee's volume. The Money Transmission Modernization Act, a model law developed by state regulators, sets a tangible net worth of at least USD 100,000 that increases with total assets, alongside a surety bond and a requirement to hold permissible investments equal to outstanding payment obligations. A principal MSB must therefore manage capital, bonding and liquidity as separate but related constraints.
How regulatory capital differs from accounting equity
The adjustments matter in practice. A fintech that has acquired another business may report substantial equity, but most of it can be goodwill and capitalized software, which bank capital rules deduct and money transmitter tangible net worth tests exclude. Losses, dividends and loans to shareholders reduce regulatory capital immediately. Regulators may also refuse to count capital that is not truly committed, such as funds that a parent can withdraw at will.
Example
A bank has risk-weighted assets of 10 billion. To meet the 4.5% CET1 minimum plus the 2.5% conservation buffer it needs at least 700 million of CET1 capital. If it holds 650 million, it breaches the buffer, and Basel-based rules restrict the dividends and bonuses it can pay until it rebuilds capital.
Role in licensing and supervision
Capital rules sit alongside other safeguards such as safeguarding of customer funds, liquidity requirements and the reserve rules applied by central banks. They also shape behavior: firms may seek structures that lower their capital needs, which can become regulatory arbitrage when the risk stays the same. A change of control or a new business line usually triggers a fresh review of whether a firm's capital is still adequate.