WASHINGTON — Discover Bank will refund $200 million to more than 3.5 million cardholders to settle charges that its telemarketers used deceptive tactics to sell credit card “add-on” products, such as credit score tracking and identity theft protection.

Discover also agreed to pay $14 million in civil penalties as part of the settlement, announced Monday by federal regulators.

A joint investigation by the Federal Deposit Insurance Corp. and the Consumer Financial Protection Bureau concluded that Discover had misled customers into buying four add-ons: payment protection, credit score tracking, identity theft protection and wallet protection. The company’s telemarketing scripts falsely implied that the add-ons were free “benefits,” regulators said. Fast-talking telemarketers skipped over costs and terms and failed to disclose eligibility requirements, they said.

Under the settlement, Discover must stop using the sales tactics and submit to an independent audit.

Discover is the second major bank to reach such a settlement in recent months. In July, Capital One Bank agreed to refund $140 million to 2 million customers and pay an additional $25 million penalty after an investigation found that the bank’s vendors had used deceptive tactics.

“We continue to expect that more such actions will follow,” consumer bureau Director Richard Cordray said Monday in remarks to the news media. “In the meantime, we are signaling as clearly as we can that other financial institutions should review their marketing practices to ensure that they are not deceiving or misleading consumers into purchasing financial products or services.”

It’s the latest sign of stepped-up enforcement action from the Consumer Financial Protection Bureau, a controversial new agency that’s considered the signature achievement of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010.

Discover cardholders who qualify for the refund will receive credits to their accounts.

Those who no longer have Discover cards will get checks.