Maintaining that service charge in hotels and restaurants was "totally voluntary", Union Food and Consumer Affairs Minister Ram Vilas Paswan on Friday said the government had approved guidelines in this regard.He added that the guidelines were sent to the states for necessary action."Government has approved guidelines on service charge. (It) is totally voluntary and not mandatory now. Guidelines are being sent to states for necessary action," he tweeted.According to the Guidelines on Fair Trade practices framed under the Consumer Protection Act, placing of an order by a customer amounts to his or her agreement to pay the prices displayed on the menu card along with applicable tax."Charging for anything other than the aforementioned without consent of the customer, would amount to unfair trade practice," reads the guidelines.It further said that the bills should clearly display that service charge is voluntary and that the service charge column of the bill should be left bank for the customer to fill up before making payment.The customer can decide whether or not to pay service charge or tip only after assessing the quality of service, and if so, how much, the guidelines state.Paswan said last week that his ministry had sent an advisory on the service charge issue to the Prime Minister's Office (PMO).If hotels levy the charge mandatorily, customers can approach consumer courts.