The 40-year-old singer starred alongside Mel C, Emma Bunton, Victoria Beckham and Geri Halliwell in the iconic girl group, and she revealed her bandmates are eager to mark the anniversary in some way, although they are still to come up with any concrete plans.
She said: "I think when there is something to say, we'll be screaming from the rooftops about it. But right now, we're just being friends and hanging out, bouncing around ideas, and we'll see what happens! We definitely want to celebrate the 20th anniversary somehow."
Mel B recently posted a picture of herself and bandmates Emma and Geri on social media, and she revealed how she came to put it online.
She said: "Emma posted a picture first so I was like: 'I'm going to post one too then!' We always have a nice time hanging out no matter where we are."
Meanwhile, Mel opened up about her relationship with Stephen Belafonte, who she has been married to for nine years.
Asked if they have plans to renew their wedding vows in the near future, she told OK! magazine: "No. This is our ninth year being married; I think you're meant to do it when it's ten or 20."
Mel added that the duo have lasted the test of time because their relationship is underpinned by a tight friendship, even though they experience the occasional tiff.
She said: "Stephen's my best friend and I actually like him! He irritates me at times, but I like him and I love him."
