Hotels and restaurants should ask customers before levying a discretionary service charge to bills, a senior government official said today. Although service charge is voluntary, most hotels and restaurants levy up to 10 per cent of the bill amount as service charge, which is considered as tip. The service charge varies from place to place. Consumer Affairs Secretary Hem Pande said that hotels and restaurants should add service charge to bills only after asking customers. Customers do not have to pay the service charge or tip if they do not like the service,, he said. The Secreatry said the Consumer Affairs Ministry will soon issue an advisory to all states asking them to take effective steps and remind consumers of their rights. Restaurants charge 12.5 per cent VAT and 6 per cent Service Tax to the bills, apart from service charges.