William is said to have invited four ex-girlfriends, while Kate has invited two ex-boyfriends.
Also on the list is movie director Guy Ritchie, but he'll be going stag since his invite doesn't have a plus one.
Kate's sister Pippa, however, will be able to bring her businessman boyfriend.
Meanwhile, the Mail on Sunday newspaper claims to have the official invitation roster. The newspaper's supposed list describes an eclectic mix - everyone from fabulously wealthy friends of Prince Charles to a favored bartender and a yoga instructor from the Caribbean island of Mustique, long a hideaway for royals and rockers alike.
The palace dismissed the newspaper's list as speculation Sunday.
It won't be clear until the day how the royal couple has balanced the protocol demands that they invite statesmen, diplomats, religious leaders, politicians and the like with invitations to the people they really want to see, particularly the crowd they made friends with when they met and fell in love at St. Andrews University in Scotland.
The Associated Press contributed to this report.