A spokesman for the former wife of the duke of York told The Daily Telegraph Fergie has plans to be out of the country on the big day even though her two daughters will be in attendance.
The newspaper reported Saturday the duchess had made other plans despite earlier media reports William had wanted her on the guest list.
"She never expected to be invited or to attend," the spokesman said. "She will be overseas at the time."
Ferguson's daughters, Beatrice and Eugenie, are close with both William and Kate and will are invite to the April 29 wedding, the Telegraph said.