The couple, who got engaged 10 months ago, are apparently flooded with work which has forced them to delay their trip to the altar, the People magazine reported.
The stars were going ahead with their wedding preparation a few months ago but things have slowed down now.
"Wedding bands were designed and Jen was deciding on a dress," said a source, adding Aniston even had a date in mind.
Aniston, 44, and Theroux, 41 are overloaded with work commitments and a massive house renovation, "wedding talk has stopped," the source informed.