The original 93/6/EEC (CAD1) directive was amended by 98/31/EEC (CAD2), to incorporate banks' own estimate of capital using value-at-risk techniques. Annex 1 models were virtually unchanged by CAD2, so there has been no change in the CAD1 regime.
A third revision of the directive 2006/49/EC was issued on 14 June 2006 and would use the new name of Capital Requirements Directive (CRD) . This came into force together with recast of a related banking directive on 20 July 2006. The main change was the adoption of Basel II guidelines into the directive.
Capital requirement (also known as regulatory capital or capital adequacy) is the amount of capital a bank or other financial institution has to hold as required by its financial regulator. This is usually expressed as a capital adequacy ratio of equity that must be held as a percentage of risk-weighted assets. These requirements are put into place to ensure that these institutions do not take on excess leverage and become insolvent. Capital requirements govern the ratio of equity to debt, recorded on the liabilities and equity side of a firm's balance sheet. They should not be confused with reserve requirements, which govern the assets side of a bank's balance sheet—in particular, the proportion of its assets it must hold in cash or highly-liquid assets.
A key part of bank regulation is to make sure that firms operating in the industry are prudently managed. The aim is to protect the firms themselves, their customers, the government (which is liable for the cost of deposit insurance in the event of a bank failure) and the economy, by establishing rules to make sure that these institutions hold enough capital to ensure continuation of a safe and efficient market and able to withstand any foreseeable problems.