The celebrity couple are focusing first on their professional commitments, Hindustan Times claims.
"If they get married next year, they will be able to focus on the wedding easily. Right now, Kareena is promoting Ek Main Aur Ekk Tu, while Saif's energy is completely focused on Agent Vinod. The final call to get married will be taken soon," said a source.
The source went on to add: "Nothing is confirmed right now. Both of them are still pondering over the possibility of getting hitched next year.
"Besides Agent Vinod, their hands are full with a lot of work in 2012. They are still discussing details with each other and their family members. Valentine's Day 2013 is an option for them."
Long-term couple Khan and Kapoor star opposite each other in the action spy film Agent Vinod, which is released on March 23.
Kapoor's Ek Main Aur Ekk Tu hits the box office on Friday (February 10).