Establishing ownership of stock depends on how the stock was purchased, according to the Securities and Exchange Commission. A brokerage firm may have purchased the stock or it may have been bought directly from the company.
A brokerage firm may have bought stock in the owner's name or in its name. Either way, the firm should have a record of the purchase if it is less than 6 years old, reports the Securities and Exchange Commission. For older stock purchases, a transfer agent for the company keeps a record of all the securities owners. Names and addresses of transfer agents are in the report that companies file with the SEC. Some companies also have an investor relations office that can provide information on their stocks.
Stocks purchased directly from the company should either be on paper as a stock certificate or listed in the company's computer records, states the Securities and Exchange Commission. For companies that are not publicly traded, the state in which they were incorporated can supply information on them. If the stock is not listed with a brokerage firm, transfer agent or the company, the stock may have been turned over to the unclaimed property office in the state of the owner's last known address.