Happy birthday or Congrats Mr and Mrs Z?

Sources are saying that the four-day "surprise" birthday party Beyonce is throwing for Jay-Z next weekend will actually be a wedding.

"Beyonce is throwing Jay a four-day birthday party, but it's really a wedding," said one source.

"Guests, including family and close friends, were told to have passport applications filed by last Friday so they can attend the bash on a yacht in St. Barts.

But insiders said the guests will also be ferried over to Anguilla for the wedding at Cap Juluca, a five-star resort with Moorish villas.

Another spy said Knowles and Jay-Z had toured the site earlier this year and approved it for their nuptials. "