Transfer Agent

A trust company, bank or similar financial institution assigned by a corporation to maintain records of investors and account balances and transactions, to cancel and issue certificates, to process investor mailings and to deal with any associated problems (i.e. lost or stolen certificates).

Investopedia Says:
Because publicly-traded companies, mutual funds and similar entities often have many investors who own a small portion of the organization, require accurate records and have rights regarding information provision, the role of the transfer agent is an important one. Some corporations choose to act as their own transfer agents, but most choose a third-party financial institution to fill the role.

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Company that issues, registers, and redeems securities on behalf of the issuer. The agent, usually a commercial bank, also maintains records of changes in ownership, cancels old securities, updates these records when securities are sold, and ensures that new offerings of securities are not overissued. If the securities offered for sale are bonds, the agent is known as a Registrar. See also American Depositary Receipt; Book Entry Security; Custodian; Depository Trust Company.

Individual or firm that keeps a record of the shareholders of a corporation by name, address, and number of shares owned. When stock is sold, the new owner through an agent presents the shares purchased to the transfer agent who cancels the old certificates and issues new certificates registered in the name of the owner. Every stock transaction does not result in a transfer since a significant portion of most issues is held in street name to support margin or for the convenience of the owner. See also registrar.