Income tax returns should not be filed using only the 26AS tax credit statement because of possibility of following errors by deductor :
Deducting your TDS but not depositing it with the tax authorities.
Deducting your TDS and depositing it in incorrect PAN or PAN of some other deductee.
Depositing someone else's TDS in your PAN.
Deducting and depositing your TDS but not filing the TDS return, or incorrect filing of TDS return.
Considering the above inadvertent mistake if Income tax return is filled only on the basis of tax credit information being reflected in form 26 AS, there is a chance of filing incorrect or incomplete Income tax return. It is therefore always advisable to file salary return on the basis of Form 16. Firstly, Form 16 acts as a check for you to verify whether your employer has deposited the whole amount of TDS that he may have deducted from your salary. Secondly, it will enable you to file Income tax return disclosing the correct taxable income and various deductions from your salary like EPF, Profession tax and TDS.
Further, it is the obligation of the employer to provide a Form 16 to all employees by 31 May of the assessment year (AY), otherwise, the employer can be liable to pay a penalty of Rs. 100 for each day by which he delays issuance of this certificate.
On the basis of above explanation it is my advice not to file income tax returns by using only 26AS tax credit statement without taking into account the Form 16 and payslips