Harry and Meghan have struck up a close friendship with Geri and Christian Horner, the Daily Mail can reveal.
The former Spice Girl and her husband invited the Duke and Duchess of Sussex to their home in the Cotswolds for lunch last month.
Geri and Christian live in a £9.2million Grade II-listed former vicarage, built in the 18th century.
It's understood that the Sussexes joined them there while visiting Britain in July – a trip during which they made their final decision to return.
The two couples are understood to have discussed what life in the UK looks like.
The ex-pop star has since been in regular contact with Meghan sharing her thoughts on a proposed move to the Cotswolds with Prince Archie, seven and Princess Lilibet, five.
Prince Harry meanwhile has been in regular telephone contact with Geri's F1 guru husband Christian, who also offered such advice.
The couple-to-couple bond has been growing in significance for the exiled royal couple as they plan their return.
Christian and Geri Horner have formed an unlikely friendship with Prince Harry and Meghan, with the couple advising the royals ahead of their move back to the UK
Harry and Meghan enjoyed a lunch at the Horners' £9.2million Grade II-listed Cotswolds home during their stay last month where they discussed the move, sources say
The Duke and Duchess of Sussex have been sounding out the Horners for tips on what their life could look like when they move back to Britain - six years after leaving for a new life in the US
A source close to the Horners said: 'Meghan and Geri in particular have become increasingly friendly and have been in ever more regular contact in recent weeks.
'Christian has also had a number of conversations with Harry. They are friends.'
They added: 'Geri is absolutely buzzing about the relationship - and she's loving being involved from the inside in their return to UK.
'Christian is a bit more circumspect - less overawed.
'But both of them are aware that the Sussexes will be relaunching themselves socially in a matter of days and they see themselves as potentially a key part of this new friendship group.'
Harry and Meghan are believed to have stayed in the Cotswolds during their recent visit to the UK – which may signal their interest in choosing the moneyed rural enclave for their next home.
The couple are understood to have spent a few days staying in a private house belonging to a wealthy associate in early July when they last came to Britain, as the Daily Mail revealed last week.
Harry and Meghan are expected to arrive in the UK to begin their new life within days, ahead of school terms beginning next week.
The precise location of their new home is being kept a closely guarded secret for security reasons.
They already have strong links to the Cotswolds, having lived in a rented £2.5million farmhouse in the area in 2018 – only moving away after the location of their house was revealed.
Earlier this year, the couple stayed in the area from where Harry took his family to see his father King Charles at Highgrove, on the southern side of the Cotswolds, and they also visited the grave of his mother Diana, Princess of Wales, at her ancestral home at Althorp, Northamptonshire.
Geri in her kitchen at home, where she hosted the royal couple
Ahead of Harry and Meghan's wedding in 2018 there were longstanding rumours that Geri, along with the rest of the Spice Girls, had been invited - though in the end only Victoria Beckham attended.
Two years later, in 2020, Geri did attend Commonwealth Day celebrations at Westminster Abbey which would turn out to be Harry and Meghan's final official engagement as working royals - though it's unclear if they met that day.
But the two couples do have a number of friends in common including Princess Eugenie with whom Harry has long been close - and whom Geri has become friendly with.