The diary: Top Hat For Becks; And tails for his mates too, says Posh.
All the male guests at the July 4th ceremony at Luttrellstown Castle, near Dublin, have been told they must wear matching formal morning suits.
But they've been told not to worry about the cost of buying or hiring the top hat and tails - it's all on the Brylcreem boy.
The couple have also agreed to foot the bill for music biz pals to fly over from the massive Prince's Trust concert in Hyde Park which takes place on the same day.
Stylist Kenny Ho, who dressed Geri Halliwell when she sang at Prince Charles'' birthday, is co-ordinating the mass outfitting for the couple's family and friends, including all of the treble-winning Manchester United team.
"We've just been told to give Kenny our sizes and he'll take care of the rest," one guest told me. "Apparently Victoria wants everything to be traditional, not glitzy like Mel B's wedding."
Victoria's outfit and those of her Spice Girl bridesmaids are still a closely guarded secret but she is said to be upset that she can't have an open-air ceremony.
The pair are being paid pounds 1million by OK! magazine for exclusive coverage of the ceremony and bosses are worried about aerial photographers from rival publications.
"Victoria really wanted a sunshine wedding in the castle's grounds but it looks like she'll have to settle for a marquee," a pal told me.