Both a Share Subscription Agreement and Share Purchase Agreement (SPA) are used to record the sale of shares in a corporation. However, a Share Subscription Agreement is used to record the purchase of shares when a corporation is issuing its own shares as opposed to the shares being purchased from a shareholder, and a Share Purchase Agreement is used when shares are sold by a shareholder rather than from the corporation issuing its own shares. In other words, a Share Subscription Agreement is a contract between an individual or entity and the issuing corporation, and a Share Purchase Agreement is a contract between an existing shareholder of the corporation and a buyer.