DOUBLE LIABILITY, in the United States, applies to the stockholders' liability in certain corporations, signifying that, in case of insolvency, the stockholders may not only lose the amount which they invested in their stock but may also be called upon ratably for the concern's indebtedness up to an additional amount equal to the full par value of the stock. This double liability does not apply to stocks of ordinary business corporations but to bank ing corporations. The laws of most States make State-chartered banks subject to double liability, and the national banking laws make double liability apply to the stock of national banks. The national bank act in providing for double liability on national bank stock provides : "except that shareholders of any banking association now existing under state laws having not less than five million dollars of capital actually paid in and a surplus of twenty per centum on hand, both to be determined by the troller of the Currency, shall be liable only to the amount invested in their shares." At the time of the passage of the act, the National Bank of Commerce of New York city met the above re quirements and so its stock became the exception to the double liability for national banks.