In case you had two employers for the particular financial year, you will get Form 16 from both employers for the respective months you served. The income tax return will be filed by combining the details of both Form 16s. But you must be careful in doing so because it might happen that your former and present employer has calculated your tax after taking into consideration the basic exemption limit. In such a case, you are not entitled to take advantage of the exemption limit twice.
The same applies to all deductions and allowances during the year, as any deduction/allowance can be claimed only once or as per the respective rules of the income tax law, even if it is reflected in both Form 16.
Further, when you switch jobs in a year, then you should furnish your previous employer's income and TDS details to your new employer in Form 12B.
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