NEW DELHI: The Telecom Regulatory Authority of India (Trai) has directed that consumers will have to be given intimation prior to start of every "blackout" day with regard to concessional voice calls or SMS offered to them by telecom service providers.

Trai said the date/occasion of the "blackout" day will also have to be intimated, as part of a direction prescribing additional measures with a view to enhance transparency in the matter of charging on "blackout" days.

The term "blackout" days refers to the days on which the service providers do not allow free or concessional voice calls/ SMS offered by them under any plan/ package. Certain guidelines are already in place as per which the number of blackout days shall not exceed five in a calendar year and no alteration in any such date is allowed after the package is subscribed to by the consumer.

List of blackout days applicable for the calendar year will be displayed on the website of service providers, before start of every calendar year and shall be published, service area wise, along with the tariff plans of the service provider, every six months.

The charges for calls or SMSs on ‘blackout‘ days will not exceed the rate in the tariff plan in which the consumer is enrolled.