The Federal Trade Commission said its first “undercover phone sweep” of funeral homes across the country had found that dozens didn’t accurately disclose costs for services to callers.

Of the more than 250 funeral businesses F.T.C. employees called, 38 either didn’t answer questions about prices or supplied inconsistent prices for identical services, the commission said. Many homes, it said, provided “materially different” prices for the same services during two separate phone calls.

Another home promised to send an itemized price list, the agency said, but instead sent a list of package prices, which don’t meet disclosure requirements.

The 39 funeral homes received warning letters in January that they had failed to comply with a law known as the Funeral Rule. The F.T.C. enforces the rule, which outlines protections for consumers shopping for funeral services.

“It’s very important that consumers are able to comparison shop,” said Melissa Dickey, an F.T.C. lawyer and a co-coordinator of the Funeral Rule. “Not everyone can go in person to pick up a price list.”

Of the funeral home that sent a list of package options, Ms. Dickey said: “You don’t have to buy a package.” The funeral home must let you buy only the services you want.

One of the homes also misrepresented local requirements for embalming, or preservation of the body after death, the F.T.C. said. Some funeral homes may require embalming as part of their own policies, but most states do not require it, the commission said, and the few others require it only in limited circumstances.

Bereaved people are stressed and vulnerable when they contact funeral homes, and in an increasingly mobile society, relatives often must make arrangements from out of state, said Sara Williams, president of the Funeral Consumers Alliance, a nonprofit group that seeks fair treatment of people seeking funeral services.

Ms. Dickey declined to share details of what F.T.C. employees had said to funeral homes during the calls. But, she said, the law requires funeral directors to provide price information on the phone. Callers don’t have to give their name, address or phone number, she said, and they needn’t be a relative of the deceased.

“The funeral home cannot refuse to give out information,” Ms. Dickey said. “They should be answering questions no matter who is calling.”

In a statement about the sweep, the National Funeral Directors Association said, “While the compliance rate certainly should be higher, the F.T.C. reported a more than 85 percent compliance rate.” That was consistent with, if not higher than, results from prior commission investigations involving secret shoppers who visited funeral homes in person, the industry group said.

Funerals can be expensive. The typical cost of a funeral with a coffin and burial is $8,300, while the cost of a funeral with cremation, including a special coffin and an urn, is $6,280, according to 2023 data from the national association, which represents about 11,000 funeral homes.

The F.T.C. didn’t recommend prosecution of the violations, but asked the homes to take “prompt remedial action” to comply with the law, which in part requires funeral homes to give written price lists for products and services to people who visit in person, and to share pricing over the phone on request. Homes that don’t comply risk penalties of more than $51,000 per violation, according to the warning letters.

The F.T.C. is weighing updates to the 40-year-old Funeral Rule. Because it predates the widespread use of the internet, the rule doesn’t address digital disclosure of prices. Consumer advocates are urging the agency to modernize the law by requiring funeral homes to post their price lists online.

Ms. Williams of the Funeral Consumers Alliance said that doing initial research electronically could help make a difficult task easier, and that requiring online price disclosures would simply recognize that “it’s how we live now.”

Some funeral homes do post prices on their websites, but they don’t always make the information easy to find, according to a 2023 report from the Consumer Federation of America, a nonprofit group. Requiring online posting would make monitoring compliance with the law easier, said Stephen Brobeck, a senior fellow with the federation. Instead of making undercover calls or visits, investigators could simply check websites.

The funeral directors association, in written comments to the F.T.C., said requiring online price disclosure was unwarranted because its data showed that the “small minority” of consumers who shopped for funeral by comparing prices were not doing so on the internet.

“Overwhelmingly, funeral consumers prefer to visit or call the funeral home they intend to use, as opposed to searching online,” the association said.

Christopher L. Farmer, the general counsel of the funeral director association, said in a phone interview that the group supported price transparency, but that funeral homes should be allowed to choose for themselves whether to disclose prices online.

Consumer advocates said more people would shop for funeral services online if prices were widely available there.

Here are some questions and answers about getting information about funerals and related services:

What else should I know when calling a funeral home for price information?

Although they are not required to do so, many funeral directors may mail or email their price lists if you ask. The funeral home can’t require you to visit it, Ms. Dickey said, but if you do go in person, you are also entitled to receive a copy of the price list there. “If they won’t give you the information,” she said, “find a different business.”

The F.T.C. offers more tips on its website.

You can also check to see if your state has an arm of the Funeral Consumers Alliance, which may have information on providers. Ms. Williams, who is also president of the alliance’s North Carolina affiliate, said her group periodically gathered price lists from funeral homes in the state and posted them on its website.

What if I have a complaint?

If you encounter a problem with services that can’t be resolved with the funeral director, most states have a funeral agency or board that may help. (The Funeral Consumers Alliance offers a list of state contacts, along with suggestions for wording a complaint, on its website.) You can also submit a complaint to the consumer affairs division of the attorney general’s office in your state. The F.T.C. also accepts complaints on its website.

When is the F.T.C. expected to announce if it will propose changes to the Funeral Rule?

A spokeswoman for the F.T.C. said no update on timing was available. Mr. Brobeck at the consumer federation said he was “optimistic” that the agency would publish a proposed update sometime this year.