If you are filing your income tax return, you may find a column to fill 8 character unique TDS number. You must know that required 8 character number is not the same as 6 character certificate number of FORM 16A (TDS certificate) which is given at right upper corner of form 16A (generally provided by bank for fixed deposit income).
If you have fixed deposit in your bank, Bank will deduct the tax on accumulated interest for the financial year and deposit it to government account without taking your permission. After deduction of tax from your account they will send you the FORM 16A (certificate of tax deducted at source for interest earned).
Usually for the financial year 2011-12 almost all bank have not deducted tax in each quarter of financial year. After deducting the amount in last moment of financial year they are sending form 16A with 6 character certificate number.
Government have given instruction to banks to file the return quarterly for TDS. After quarterly filing TDS return, Income tax department provides unique 8 character TDS certificate number for each deductee.
So it is responsibility of bank to get 8 character TDS certificate number from Income tax department and send the information to the deductee on quarterly basis.
You can expect the bank to follow this instruction for this financial year (FY-1012-1013) onwards.
For the mean time while you can keep “Unique TDS certificate number” column blank in the income tax return form as it is not compulsory to put the number.
Never put the 6 character FORM 16A number, as it is of no use. This 6 character number is not given by income tax department, so never put this number in Income tax return form in any way.