The band members feel 'every artiste in the world' would want to perform at the high profile event, reports contactmusic.com.
The couple announced their wedding plans last week.
has offered to sing for the couple and said they would love to let the
British royals set a list of songs for the reception.
'Every artist in the world would sing at that wedding,' said band member Shane Filan.
Egan added: 'We'd be honoured to play at a royal wedding, that would be
amazing. I mean, it would be dependent on what they would like...We'd
let them choose the songs really, that's generally what we do if we sing
at a wedding.'