The fab two tie the knot on 4 July and their wants are simple. All she is after is money. She has said so: it is official. No plated toaster, no fish forks by request. There is no list at Harvey Nicks or London Trading Company or Thomas Goode which is where the Wessexes had theirs. Instead she has asked that her wedding presents be shopping vouchers or cash - convertible units of exchange, in whichever form is most convenient to the giver. Just stick a cheque in the post. Or American Express might do nicely.
The Spice-Beckhams are not alone - and it is not merely the arrivistes who take the money. Courts, the furniture people, have done a survey showing that one in five of 25- to 34-year-olds are going for the new "cashback" weddings. The money-order wedding, they say, is the trend among their customers - and Courts is for those who have been middle class for years.
Indeed at the "smarter" weddings these days the list is not at Harrods or even Selfridges, but at good old Marks and Sparks. And we all know the reason you shop at M&S is so you can take unwanted things back. Even if they won't give you a cash refund, you can at least use the credit to stock up the freezer with instant meals for the next week or month or year.
Is this a now a socially tolerable trend: to ask for money and feel no shame? "It depends if it is a shopping voucher or straight cash," says Sandra Boler, editor of Brides magazine. "In English society it is not acceptable to give money to the person; it is acceptable to give money to the shop."
In other cultures, as Ms Boler points out, cash giving is actually expected. As a Greek bride dances before her guests they pin notes to her dress in appreciation - though whether Posh Spice would want her white designer number covered with grubby tenners is open to doubt.
You can call it cold-blooded, or you can call it solid common sense and realism in the hard cold world of today. "People have been living together for years by the time they marry," says Anya Sugden, who did the Courts survey. "They already have homes - no need to furnish them. They have a good supply of towels already and they wouldn't know what to do with a nutmeg grater even if it was silver-plated. If they do want furniture it will be something big and special like a bed or a sofa, too big for one person to give. But if they all give money, it can combine for that."
The cash wedding is not entirely a new phenomenon. Venetia Darwin was married in 1963 and, after initial doubts, asked for cash. "We were setting up home abroad and spent the money on furniture and household equipment when we got there. It was much simpler that way - especially as we would have had to pay tax on any new stuff that we took with us."
She got her furniture but then she had her doubts. "A money gift puts you under an obligation, in the way that other presents don't. I felt guilty at asking, and guilty at getting. And it was interesting: the people who could afford least gave most. I hated that, and found it very embarrassing," she said.
Worse still: "There was one very vulgar woman in the village who I didn't like and who was no friend of mine, but who sent such a large cheque that my father had to invite her to the wedding. It was as though she was paying an entrance fee."
It harks back to the ancient and venerable potlatch system. Potlatch occurs in primitive subsistence societies such as the Inuit-related tribes of western Canada. The idea is that you give huge expensive presents to the head of your clan, far more expensive than you can afford. Nor do you expect to get similar presents back, but it puts the chief under a massive social obligation to you, makes you part of his circle of protection, and come famine, or hardship, or tax demands, he has to pass on the odd dried fish or lump of seal meat to see you through.
The system works only in hierarchical societies that have an identifiable aristocracy or elite. But the wedding present rituals of British society can be seen as remnants of the potlatch system. And turning it to cash merely brings it up to date.
So, come the next market downturn, Posh and David might find they have to provide for more hangers-on than they expected. It may also make for a new line in congratulatory phone calls. "Darling, I'm so happy for you both. My credit card details are Mastercard, expiry date June 2000, number ..."