The Telecom Regulatory Authority of India (TRAI) has introduced a slew of regulations to deter pesky telemarketing calls and messages following a surge in user complaints.

The TRAI has placed a cap on the number of texts a user can send per day at hundred. The regulatory body has also barred commercial calls or messages between 9pm and 9am.

In India, telemarketing activity has soared in the recent years following the rise in mobile usage in the country of over two billion people and with more than 700 million subscribers.

Earlier attempts by the government to rein in telemarketers have not been successful. This time, the new rules come with a "national do not call" list. Any mobile user can register their numbers on the list by sending a message to 1909.

According to the BBC, TRAI said that the number of unsolicited commercial calls have reduced significantly since the regulatory body introduced the "do not call" registry in 2007, but the number of text messages surged.

"The first step has been taken but the more important challenge will be that we are able to implement it as well," Communications and IT Minister Kapil Sibal said.

Violation of the rules will lead to hefty fines or a termination and blacklisting of the telemarketer.

"Its not the severity but surety of penalties will lead to customer receiving a sigh of relief," said minister of state for communications and IT Sachin Pilot.

However, the TRAI has relaxed the new rules for some categories of users.

"The authority received representations from the customers, telecom service providers and their associations stating that in view of the restriction imposed, the customers who need to send non-commercial messages to their employees, agents etc. for their genuine day to day operational requirement are not able to send such messages," TRAI said.

"The authority has duly considered the representations and is of the view that non-commercial communication under certain categories need to be excluded from the limit of one hundred SMS per day per SIM," it added.

The new rules would also be relaxed on festival days.