Trai took the step after the telcos did not pay up despite several reminders over the last few years. The maximum amount needs to be paid by state-run Bharat Sanchar Nigam Ltd (BSNL) and Mahanagar Telephone Nigam Ltd (MTNL), amounting to around Rs 50 crore for defaults over 8-10 years, followed by Bharti Airtel (Rs 20 crore), Vodafone Idea (Rs 15 crore) and Reliance Jio (Rs 12 crore). The private telcos haven’t paid penalties for a period of 10 months to three years, said an official.