Tier 1 capital refers to a bank’s equity capital and reported reserves. This highly important metric is used to measure the capital adequacy of the bank, and to ensure it is able to endure financial shocks without having to resort to layoffs or other austerity measures. The Tier 1 capital ratio specifically compares a bank’s equity capital with its total risk-weighted assets, which are assets the bank holds weighted by credit risk.

The two primary components of Tier 1 Capital are Common Equity Tier 1 (CET1) and Additional Tier 1. Common Equity Tier 1 is the more important component, as it is designed to capture the basic and permanent core capital of a bank. It includes cash, retained earnings and disclosed reserve accounts, and is used to measure a financial institution’s assets compared to their liabilities. Additional Tier 1 is less important, as it includes instruments and securities that are not as secure or solid as the CET1 component. These include the aforementioned disclosed reserves, and various components such as pre-paid expense and minority interests.

The Basel III Accord is the primary banking regulation that sets the minimum Tier 1 capital ratio requirement for banks, requiring it to be greater than 6% of their risk-weighted assets. Both domestic and international banks must ensure they meet these requirements, or else they may face financial penalties, administrative sanctions, and even criminal charges. Additionally, if a bank has too low of a Tier 1 Capital ratio, it may face liquidity problems and may even be forced to wind down its operations.

Thus, Tier 1 Capital is a very important metric for assessing the financial health of institutions. They must ensure they have a high enough Tier 1 Capital ratio while complying with Basel III requirements, in order to remain a viable and viable profitable entity. Furthermore, governments, financial institutions, and stakeholders often monitor this number carefully, as it is indicative of the institution’s near-term viability.