But filing tax returns is a good practice even if you will not pay any tax. You can file a nil return. It helps in many ways -
Proof of Earning
The ITR will be a proof of your income. It will come handy in many situations like overseas travel, financial planning and tax scrutiny.
Carry Forward losses
You can carry forward capital losses for eight years and write it off against capital gains. But this is possible only if you have filed your ITR in the year when you made a loss.
Loans and Insurance
IT Returns are useful as documentation while applying for home loans as they show proof of regular income. They can also equip you with better chances to get a high insurance cover.
Claim Tax Refund
TDS might have been deducted from your income and while filing returns you realise that your investments etc. can help you get a refund.But do note that you can claim tax refund only if you have filed your tax returns.
ITR is a key component of documentation for many purposes such as visa processing, loan processing etc.