The primary federal law governing debt collection, the Fair Debt Collection Practices Act, was passed in 1977, and the debt-collection industry has for years sought official guidance on how and when digital messages can be sent.

More than 70 million Americans have a debt that has reached the collection stage, and complaints about collection tactics have flooded federal regulators. The consumer bureau received more than 80,000 such complaints last year, most of them about collection attempts over debts that consumers denied owing. Consumers also complained frequently about abusive collection tactics, including threats.

Large debt-collection companies have been cautiously supportive of the consumer bureau’s efforts, which they hope will deter the industry’s worst actors.

“We’re thrilled that the rules are out there,” said Jan Stieger, the executive director of the Receivables Management Association International, which represents debt collectors. “We’re very happy to see that email, text messages and voice mail are addressed, with clear guidance about how to use them lawfully. That’s a major step forward.”

Consumer groups praised some of the proposed changes, like the ban on making multiple calls a day to customers and a prohibition on collectors suing or threatening to sue over a debt that is beyond the statute of limitations for collections. (How long an unpaid debt remains valid varies by state.)