Clubbing of Previous Empoyer Income

If the employee is having any income frm the previous employer, then it is the option of and burden on him to submit the details of the income from the previous employer (in form 12B), and present employer is under no obligation to deduct the tax on any income from previous employer....unless the employee submits the details in the said form..............

moreover he also hve the option to choose out of more than one employer, as to who will dediuct the tax on the total income.......in any case, if the employee don't specify any such details, the present employer is required to deduct tax on the income given by him only....no such declaration is necessary......

Very good answer has been given by Mr. Ashish......It is not the responsibility of the deductor until and unless employee disclose it to the deductor about his previous salary and in such case the present employer should deduct TDS on the present salary paid by him.