Most states have requirements as to the minimum capital of their banks. In some states the amount required is the same throughout the state; in others the amount is either graded according to the population of the domiciling city, or varies with the business done by the bank. The minimum capital required ranges from $5,000 to $50,000, the banks in the eastern and east middle states having the largest. Since the national banks up to 1900 had to have $50,000 or more capital, and $25,000 after that date, the smaller banks were obliged to take out state charters. For this reason state banks are more ubiquitous. The adjustment of capital to population serves roughly to make the responsibility of the stockholders vary with the size of the banks, and also puts a check on excessive competition.

The states also vary in their requirements as to authorized, subscribed, and paid-in capital. There is a tendency, however, to follow the national bank system in this respect and to shorten the period within which capital must be fully paid. Most states require the accumulation of a surplus equal to 20 per cent of the bank's capital. The tendency is to require larger surpluses and faster accumulation of them. The declaration of dividends except out of net earnings is usually prohibited, and some states provide elaborate rules for the calculation of net earnings. Most states follow the National Bank Law of 1873 and provide for the assessment upon stockholders of any impairment of capital. Since most states require stock to be fully paid, the liability for unpaid subscriptions is unimportant. There is a tendency also to impose a "statutory liability" upon stockholders beyond the stock held by them, usually a double liability.