Dear sudhanshu,
I agree with you that there is no provision in income tax which is related to rendering of services. But if it is allowed then will become a lacuna in law.
Now tell me one thing:-
If we talk about very big companies...... they prepare their balance sheets monthly.
While preparing balance sheet of september 2009 they would also have made provision for the expense incurred on 29.09.2009 according to accrual concept.
Now when they make the provision then the liability will arise there is no doubt because they would have credited the party's a/c while making the provision.
Now what u say?