He is required to keep record of all the transactions of his business, popularly known as accounting records. These records include cash book, ledger, journal, sales register, purchase register etc. He is required to get his accounts audited from a chartered accountant once his total turnover during a financial year exceeds Rs. 60,00,000/-.
A sole proprietorship firm shall require a TAN number once it is legally required to get his accounts audited. So long as it is not required to get his accounts audited, i.e., its turnover does not exceed Rs. 60,00,000/- TAN number is not required for it and it is legally not liable to deduct TDS for the payments made to parties for expenses.
However shop license and other licence from Corporation will be required.
If it is a trading concern and its turnover exceeds the prescribed limit ( different for different states) VAT registration has to be taken.
PAN should be taken and income tax returns filed if the income exceeds individual tax limits. TAN needs to be taken only if turnover exceeds 60 lakhs ( from next year present 40 lakhs).
Central excise or service tax registrations if turnover or service revenue exceeds prescribed limits will have to be taken when required.