Value added tax in Nepal applies to the supply of goods and services by registered businesses, and the line between those that charge VAT and those that do not is drawn by annual turnover. A business whose taxable turnover crosses the prescribed threshold within a fiscal year is required to register for VAT and to charge the tax from that point onward. Crossing the threshold does not give a business a choice. Once turnover reaches the limit the registration duty arises, and trading without it attracts penalties while customers presented later at the department. Below the threshold a business may still register voluntarily, which many choose because registration allows recovery of input tax on their own purchases. The practical trigger is a running twelve-month turnover figure, not a single large sale. A trader who lands a big contract must watch the year's total carefully, because the department computes the limit from cumulative taxable supplies. Beginners should track a simple running total and review it monthly, so the decision to register is planned and never forced by a surprise notice.