The Finance Ministry has already started the budgetary exercise in mid-August, two months ahead of schedule, in order to have wider consultations with stakeholders.
Beginning with Commerce, Textile and External Affairs Ministries on September 4, the consultations with different government departments would conclude on September 28.
The consultations would focus on expenditure proposals for 2016-17 and revised estimates for 2015-16.
The Budget division of the Finance Ministry has also issued the detailed guidelines for firming up the expenditure proposals for the next fiscal.
In addition, various government departments make expenditure proposals to the Finance Ministry.
The Union Budget is traditionally presented on the last working day of February.