\Reserve city\ (Banking) In the national banking system of the United States, any of certain cities in which the national banks are required (--U. S. Rev. Stat. sec. 5191) to keep a larger reserve (25 per cent) than the minimum (15 per cent) required of all other banks. The banks in certain of the reserve cities (specifically called {central reserve cities}) are required to keep their reserve on hand in cash; banks in other reserve cities may keep half of their reserve as deposits in these banks (--U. S. Rev. Stat. sec. 5195).