The Financial Services Agency released a new set of rules Friday to upgrade protection of customers by requiring insurance firms to become more accountable for policies they sell.

The insurance business law includes a similar requirement, but it is rarely practiced reportedly because a contract involves a great many documents and salespeople often mention nothing except the benefits of their products.

The new rules, which take effect in January, require that sales representatives show written documents explaining key information in easy terms when they market policies.

An example is an outline of contract conditions and possible cases of nonpayment of benefits.

The FSA mapped out the rules after a raft of complaints from customers who purchased policies without fully understanding their terms at a time when insurance products have become more and more complex.

Key information required to be listed on the documents also includes that customers must disclose any illnesses they have, the amount of premiums they will receive upon a policy's maturity, and possible cases in which premiums may be hiked.

The documents will require sales representatives to verbally explain insurance products to prospective customers.

Earlier this year, the FSA slapped Meiji Yasuda Life Insurance Co. with a business suspension order over illicit sales practices, including cases in which sales personnel sold policies without sufficiently explaining that customers bear a responsibility for disclosing if they suffer any illnesses.

The company later refused to pay out insurance money to such customers on the grounds that they had concealed their illnesses.