1) PAN Card
It's extremely important that you keep your PAN Card ready to insert the correct PAN Number. Re-check the PAN Number once again before filing your tax returns.
2) Form 16 issued by the employer
This will help you determine the exact amount of salary income and all other relevant details pertaining to SEC 80C and other tax breaks, the proofs of which have been handed over to the company. An extremely important document if you have salary income.
3) Bank statements/passbook
This will help you know the exact interest income to add from your interest on savings bank account to the total income. Interest on savings account up to Rs 10,000 is currently exempt from Income Tax. However, you must declare the same when filing tax returns.
4) Bank fixed deposits
Also, keep your bank fixed deposits ready, which will help you add interest income from fixed deposits to your total income. Remember, interest from bank deposits has to be added to income to determine tax liability.
5) TDS certificate issued by the bank
You may not need the above, if you have a TDS certificate from the bank, showing the exact amount of tax that has been deducted from your fixed deposits.
6) Form 26 AS
This shows the tax credit you have received from your employer or the bank and is a summary of all the tax you have paid, in the form of TDS. Click here for an article on how to view your tax credits
7) Donation receipt
If you have made donation to an eligible institution you should keep the receipt issued by the institute you donated to and claim tax benefit under SEC 80G. Remember, that the receipt must bear the organisation's PAN number.
8) Sec 80 C documents
Keep all Sec 80C eligible investments like LIC, NSC, PPF handy to claim deductions. You may also include Interest paid on housing loan.