All business entities engaged in the sale of goods (traders and manufacturers) need to have a Value Added Tax (VAT) Registration, often called TIN Registration, once their annual turnover crosses Rs. 5 lakh (Rs. 10 lakh in some states). The tax needs to be collected from consumers and deposited in a designated bank account to the state government. You then need to file VAT returns each month if you're running a private limited company and quarterly if you're running a partnership, LLP or proprietorship. This needs to be done on the 20th of each month for the previous month.