As a Band Member

Before Westlife, Egan and Feehily were with Filan in a band known as I.O.U. with other Sligonians Derrick Lacey, Graham Keighron and Michael "Miggles" Garrett. He partly wrote the IOYOU's song Together Girl Forever. For 6 months, Shane's mother, Mae Filan, tried to phone Louis Walsh (who is also the manager of Boyzone). Eventually, she was able to speak to him and talked about her son's band. 3 of them were dropped and the other 3, Shane, Kian and Mark, joined ventures to finding 2 more slots for the band. Then they were joined by nicky Byrne and Brian McFadden to form Westside. The name of the band then changed to Westlife as there were already a number of bands with the name Westside.

Filan, along with Mark Feehily, was the lead singer in Westlife. Their first album was released in November, 1999, titled Westlife. With Westlife, Filan has received twenty-eight platinum discs and sold 40 million records worldwide.

Songs were found to be Filan's co-written songs. No other details whether it's for Westlife or not.

He has also written songs for other artists, (together with his former bandmate McFadden):

In the week beginning 26 April 2010, an unreleased solo song by Filan called "Beautiful In White" leaked onto the Internet, but it was credited as being recorded by Shayne Ward instead of Filan.