“Others realize the issue when they look closely at their confirmation emails and see they were not sent by the hotel at all,” city officials said.

There have been over 1,800 nationwide consumer complaints against GuestReservations.com and BookOnline.com, reported to The Better Business Bureau, according to Chiu.

BookOnline.com has the lowest BBB rating of the two, with an “F.”

“Scams like this don’t just drain a traveler’s wallet, they wear away the trust San Franciscans place in the people and institutions meant to serve them,” José Cisneros, the city’s treasurer, said. “The City Attorney’s lawsuit sends a clear message to bad actors targeting our residents, businesses, and tourists: San Francisco is fighting back.”

San Francisco launched a portal earlier this year called “StopScams SF” to protect consumers against these schemes, Cisneros said.