'Posh Spice' Victoria Beckham, 43, posted a picture on social media of all five stars, believed to have been taken in the London home of 'Ginger' Geri Horner, 45.
Beckham said in the Instagram post: "Love my girls!!! So many kisses!!! X Exciting x."
They are thought to have met up to discuss possible future band projects which could earn them a reported £10m each.
Beckham, Horner, 'Scary' Mel Brown, 42, 'Baby' Emma Bunton, 42, and 'Sporty' Mel Chisholm, 44, last performed as a five-piece at the London Olympics in 2012.
Fashion designer Beckham is believed to have decided the time is now right to work together again after previously being reluctant to reunite.
She has reportedly been given assurances by pop supremo and the band's former manager Simon Fuller - who is also behind the new ventures - that her vocals will not be needed, according to The Sun.
The stars, who had a string of hits in the late 1990s until 2000, are reportedly considering TV projects in China, a new television talent show, endorsement deals and a compilation album celebrating their greatest hits.
The "girl power" group's hits include Wannabe, Spice Up Your Life, Do It, Stop, Too Much and 2 Become 1.
It is believed they will not do a full tour due to family and business commitments.
The Sun quoted a source as saying: "Now that she's a top designer Victoria is concerned about singing but she wants to make money to pump back into her business."
Some Twitter users were positive about the speculation of a reunion.
@JRDoyle181 wrote: "My dream since 3rd grade! @victoriabeckham has to come back to."
@SirCregan said: "Brilliant I can't wait... Whooooooooo!"
And @emmabnowandthen said: "I hope it is true and to anyone who is asking who need the money… No one in their right mind would turn down 10M!"
But @rocanwa suggested they should not get back together, saying: "Once is enough, no thanks."
@AngeloT01 said: "I detest when singers come back to reunite & sing. Oobviously need the cash."
And @PhilHyde9 said: "Can we pay them not to?"