A treasury stock or reacquired stock is stock which is bought back by the issuing company, reducing the amount of outstanding stock on the open market ("open market" including insiders' holdings).
Stock repurchases are used as a tax efficient method to put cash into shareholders' hands, rather than paying dividends, in jurisdictions that treat capital gains more favorably. Sometimes, companies repurchase their stock when they feel that it is undervalued on the open market. Other times, companies repurchase their stock to reduce dilution from incentive compensation plans for employees. Another reason for stock repurchase is to protect the company against a takeover threat.
The United Kingdom equivalent of treasury stock as used in the United States is treasury share. Treasury stocks in the UK refers to government bonds or gilts.
When shares are repurchased, they may either be canceled or held for reissue. If not canceled, such shares are referred to as treasury shares. Technically, a repurchased share is a company's own share that has been bought back after having been issued and fully paid.
The possession of treasury shares does not give the company the right to vote, to exercise preemptive rights as a shareholder, to receive cash dividends, or to receive assets on company liquidation. Treasury shares are essentially the same as unissued capital, which is not classified as an asset on the balance sheet, as an asset should have probable future economic benefits. Treasury shares simply reduce ordinary share capital.
On the balance sheet, treasury stock is listed under shareholders' equity as a negative number. It is commonly called "treasury stock" or "equity reduction". That is, treasury stock is a contra account to shareholders' equity.
One way of accounting for treasury stock is with the cost method. In this method, the paid-in capital account is reduced in the balance sheet when the treasury stock is bought. When the treasury stock is sold back on the open market, the paid-in capital is either debited or credited if it is sold for less or more than the initial cost respectively.
Another common way for accounting for treasury stock is the par value method. In the par value method, when the stock is purchased back from the market, the books will reflect the action as a retirement of the shares. Therefore, common stock is debited and treasury stock is credited. However, when the treasury stock is resold back to the market the entry in the books will be the same as the cost method.
In either method, any transaction involving treasury stock cannot increase the amount of retained earnings. If the treasury stock is sold for more than cost, then the paid-in capital treasury stock is the account that is increased, not retained earnings. In auditing financial statements, it is a common practice to check for this error to detect possible attempts to "cook the books".
In the United States, buybacks are covered by multiple laws under the auspices of the Securities and Exchange Commission.
In the UK, the Companies Act 1955 disallowed companies from holding their own shares. However, the Companies Act 1985 later repealed this.