After photos surfaced last month of the talented duo working in the studio, Simpson announced the pair will release new music by November.
"It is a smack bang duets [album]," the 17-year-old singer told the Sydney Daily Telegraph this past weekend. "Justin has been a good mate of mine for a while. It's just us writing."
He added, "He told me he felt like I'd figured myself out and have grown into what he knows I will be so he was like, ‘I see you as that guitarist, singer, songwriter you've always wanted to be.' I play all the guitars on the album."
Fans of the two singers have been hoping for this news for quite some time.
In July, Simpson Tweeted that he was "hanging around the kitchen island playing my family a bunch of new music. @JustinBieber what we've created is incredible mate."
The rumors didn't stop when Simpson posted a snippet of a new track on Instagram. Unfortunately, it was later deleted.
Simpson opened up for Bieber during his Believe tour in 2012 and 2013. They would also bond off-stage, such as when they enjoyed the sights and sounds of Paris during a tour stop.
"He's a great guy to tour with," Simpson told E! News. "I had an awesome time in Europe."