Sir: Through your esteemed newspaper, I request all those people who frequently visit restaurants that they should not pay sales tax if the restaurants do not mention national tax number (NTN) and sales tax number (STN) in their invoices. It has been learnt through the social media that restaurants do not charge sales tax when they are asked to show NTN or STN. Many restaurants take sales taxes from customers and do not file it. The government must take action in this regard. MUBASHIR MEHMOOD Via Email