The deal created a big splash in Columbus, which needed a headline grabber to sell tickets. It also allowed the Flyers to clear cap space to sign goalie Ilya Bryzgalov.
Carter's agent, Rick Curran, confirmed the deal on Thursday afternoon. He said he was stunned by the news after being told repeatedly by Flyers officials that the club was not discussing trading Carter to the Blue Jackets.
"That deal is done," he told The Associated Press.
Carter's presence finally gives the Blue Jackets a top-line centre to pair with their best player, Rick Nash.
Voracek, a first-round pick in the 2007 draft, had 14 goals and 32 assists a year ago.
The linchpin of the deal was clearly Carter. With the Blue Jackets' fan base flagging and with the franchise saying it lost $25 million last year, a dramatic move was needed.
Carter, 26, instantly becomes the best centre to ever play for Columbus.
The six-foot-three, 200-pounder agreed in November to a $58-million, 11-year contract. Beginning next season, Carter's salary-cap hit will be $5.27 million, slightly above the $5 million against this season's cap. The contract also included a limited no-trade clause.
But the Flyers needed to clear a significant amount of cap space if they wanted to sign Bryzgalov, an acquisition from Phoenix who would help rid them of their three-pronged rotation from last year. The Flyers have until the end of the month to strike a deal with him.
Last season, despite having the East's top record for most of the year, Philadelphia struggled at the end, settled for the No. 2 seed, and lost to Boston in Round 2. In the playoffs, they were forced to use three netminders: Sergei Bobrovsky, Brian Boucher and Michael Leighton.
Carter has 181 goals in his six full seasons in the NHL, all with the Flyers. He has had 46, 33 and 36 the last three seasons.
Voracek, who turns 22 in August, was the No. 7 pick overall just four years ago. The native of Czech Republic had nine goals and 29 assists as a rookie in 2008-09, when the club made its only post-season appearance. The 6-2, 214-pounder had 16 goals and 34 assists a year later.
The Blue Jackets owned the No. 8 pick in Friday night's first round of the NHL draft in St. Paul, Minn.
Curran said earlier this week he had received assurances from the Flyers that they were not even discussing a deal with Columbus which would involve Carter. He said he and Carter had gotten word of the trade moments earlier on Thursday and both were stunned by the news.
"The only ones more surprised than you by the trade are Jeff and me," he said.
AP Sports Writer Dan Gelston in Philadelphia contributed to this report.