Leaked details from Mariah Carey and James Packer’s prenuptial agreement reveal that owning more than one private jet can make life complicated.

The high-profile pair, who became engaged in January after less than a year together, recently announced they were having relationship difficulties after a disagreement while on holiday in Greece.

With the future of their engagement remains uncertain, entertainment site TMZ has released details of the wealthy pair’s prenup, which dictates the pop singer would pocket $A7.8 million per year of marriage, should the nuptials go ahead.

Carey has two children with former husband Nick Cannon. Photo: Getty

The singer would be entitled to a capped total of $A39 million should the couple divorce – a number TMZ claimed Carey was dissatisfied with.

If the couple does eventually tie the knot, the section detailing what is and what is not a gift might detract from the romance.

“Except for gifts between them for their engagement, wedding or on birthdays and anniversaries, no item of jewellery and/or personal adornment costing over $US250,000 ($A325,000) will be deemed a gift unless accompanied by, or promptly followed by, a writing specifically stating ‘This is my gift to you.'”

A separate section begins to outline just how much Carey can drop on clothes using Mr Packer’s credit card each month – but the amount was left blank.

Finally, the section titled transport reads a little differently to the average couple’s, with Mr Packer’s lawyers detailing the instances Carey would be permitted to use one of the billionaire’s private planes.

“James shall provide the use of one private aircraft, of his selection, for Mariah’s personal use, or that of her children and nannies only when James, in his sole discretion, determines it is appropriate to do so,” reads the document.

The site claims Carey has demanded a $50 million lump sum to end the engagement.