Have you tried to book a hotel room or purchase a concert ticket and, when you click to pay, there are mounds of additional fees? Attorney General Andrea Campbell says these are what are known as hidden “junk fees,” and her office is trying to put a stop to it.

“Many times, junk fees only come up after you’ve put in your personal billing information. That way, the business has reeled you in and they’re more likely to make a profit,” Campbell said Monday during a news conference at her Boston office.

New regulations from the attorney general’s office make it clear that hidden “junk fees” and related billing practices violate the Massachusetts Consumer Protection Act .

Campbell says the regulations also impose a number of rules on businesses to prohibit unfair and deceptive practices, such as most prominently displaying the total price of a product and making it more straightforward to cancel subscriptions online.

The goal is to put the onus on the business to describe and disclose the fees — not on the consumer to find it, Campbell said.

She says trial offers often come with hidden costs, too. “I’m talking about that app you downloaded with a seven-day free trial, forgot about it after inputting your credit card information, and you’re charged every month without realizing it,” she said.

“Make it clearer to our consumers what they are paying for, to give them the option to proceed with their transaction or to opt out of it,” she said.

The new regulations, announced during National Consumer Protection Week, will go into effect in early September — which Campbell says will give businesses time to come into compliance.

“This will put the power back into the hands of our consumers, helping them to avoid unnecessary and unwanted costs and keeping their hard earned money in their pockets,” Campbell said.

AARP Massachusetts State Director Jen Benson says 85% of Americans have experienced a hidden or unexpected fee for a service in the last two years.

“They hit those on fixed and modest incomes like older adults even harder,” Benson said in a statement. “We are especially pleased to see that these changes include clear definitions of unfair and deceptive practices and provide easy to understand cancellation information.”

Massachusetts Bankers Association President and CEO Kathleen Murphy told GBH News they are reviewing the attorney general’s rule. “The banking industry is obligated to abide by state and federal laws and regulations that mandate that all fees are conspicuously posted so their customers understand the services for which they pay. It is for this reason that we continue to take exception to categorizing these legitimate, fully disclosed fees, as ‘junk fees.’”

Consumers who believe they have been subject to an unfair or deceptive business practice, including in relation to “junk fees,” may file a consumer complaint or call the Attorney General’s Consumer Hotline at 617-727-8400.