One of the main issue faced by subscribers in Mumbai and Kolkata telecom circle is that, when they move out of this cities to others parts of their states, they incur heavy roaming charges. To put an end to this uneven roaming charges within a state, Department of Telecom (DOT) has proposed to merge Mumbai telecom circle with Maharashtra and Kolkata telecom circle with West Bengal. There is also plans for merging  Uttar Pradesh West and East telecom circle together.

It is at proposal stage to merge Kolkata with West Bengal and Mumbai with Maharashtra, like Chennai has been merged with Tamil Nadu circle. The DoT will take it up after getting TRAI’s recommendation on auction of 900 Mhz and 1,800 Mhz” an official source told PTI.

Mumbai & Kolkata Telecom Circle to merge with Maharashtra & West Bengal - DOT

Earlier in 2005 Dayanidhi Maran, telecom minister at that time has started this process of merger, thus to avoid subscribers from paying roaming charges within a state. During that time Telecom Regulatory Authority of India (TRAI) has merged Chennai telecom circle with Tamil Nadu telecom circle. 

At present, roaming charges between metro and their respective states are either minimal or nil due to fierce competition in market. Merger of circles will formally lead to end of roaming provision with same state.