From Longman Business DictionaryTier 1 capitalˌTier 1 ˈcapital (also first-tier capital)BANKINGFINANCE one of the two categories into which a bank’s capital is divided, consisting of the most central and important types of capital. According to banking rules, banks must keep a certain amount of Tier 1 capital to protect them against failingTier 1 or ‘core’ capital consists of common stock, retained earnings, and preferred stock.The agreement called for the bank to maintain Tier 1 capital of at least 6% of its assets. → capital
