Cheryl Cole, Nadine Coyle, Sarah Harding, Nicola Roberts and Kimberley Walsh joined the band in 2002, but have spent the last few years focusing on solo projects.
Now they're stepping back into the spotlight together by recording a track for Britain's annual Children In Need drive, reported Contactmusic.
The song will be unveiled on October 19, ten years after they gave their first performance together after forming on UK TV talent show Popstars: The Rivals.
"They've been working with their old producers, Xenomania, and what they're coming up back with is pure pop perfection. They're all really excited," a source said.
