Rudolph W. Giuliani was served with a notice of his indictment in the Arizona election interference case on Friday night, becoming the last of the 18 defendants to receive the notice after nearly a month of unsuccessful attempts by the authorities.

The indictment against Mr. Giuliani, Donald J. Trump’s former personal lawyer, and others includes conspiracy, fraud and forgery charges related to their attempts to change the results of the 2020 election in the state in favor of Mr. Trump, according to prosecutors. Among the other defendants are Mark Meadows, the former White House chief of staff, along with all of the fake electors who acted on Mr. Trump’s behalf to keep him in power despite his defeat there.

Richie Taylor, a spokesman for Kris Mayes, Arizona’s attorney general who brought the indictment, said that Mr. Giuliani was served on Friday night at around 11 p.m. in Palm Beach County, Fla., as he left his 80th birthday party. “The agents by no means disrupted his event. They waited to serve him outside as he left,” Mr. Taylor said.

Mr. Giuliani’s spokesman, Ted Goodman, confirmed in a statement on Saturday that Mr. Giuliani was served “after the party, after guests had left and as he was walking to the car.”

“He was unfazed and enjoyed an incredible evening with hundreds of people, from all walks of life, who love and respect him for his contributions to society,” Mr. Goodman said. “We look forward to full vindication soon.”

Mr. Giuliani is expected to appear in court on Tuesday unless the court grants a delay, Mr. Taylor said. A trial in the Arizona election interference case has been tentatively set to start in mid-October.