The follow-up to 2007's Change was expected to be released at the end of this year, but the girls have now announced that they need more time to work on songs.
"We were supposed to release an album this year and we decided against it," Keisha Buchanan told the Daily Star. "With each album we feel we've produced a better one when we have been given time to write about stuff - and we have been through so much this year alone.
"I think sometimes people forget we do write our own material. Even when we have a co-writer, there can be 12 people writing one sentence and we're writing the bulk of the song. We want to feel inspired."
Buchanan added that a similar relaxed approach was taken with Taller In More Ways, their last album with Mutya Buena.
She said: "We had nine months 'cos Mutya was pregnant. It was great - we got to try out loads of stuff. We wanna do that again and not mess the album up by rushing something."