JLS are set to reunite next month at Frankie Sandford's wedding to footballer Wayne Bridge.
The Saturdays star has asked the quartet to perform on her big day, which will include a lavish ceremony at Woburn Abbey.
Frankie, whose bandmate Rochelle is married to Marvin Humes, "is very close with all the boys and has asked them to sing a short medley for her nuptials", an insider told the Daily Mirror.
"She wants it to be a really special cosy occasion. Guests have been asked not to take photos on their mobile phones. It's going to be very private."
This will be the first time the former X-Factor contestants, JB Gill, Marvin Humes, Aston Merrygold and Oritse Williams, will perform together following their farewell tour last year.
After appearing on the hit ITV reality series, the pop four-piece went on to score 10 Top 10 singles and scoop five number one hit singles, including their debut smash hit Beat Again, which was released in 2009.
Frankie, 25, and Wayne, 33, are said to be using Bentley's Entertainment - who arranged Victoria and David Beckham's special day in 1999.
Instead of receiving wedding gifts, guests are being asked to donate to the mental health charity Mind. The couple became patrons after Frankie battled depression.