Sounding off on The Nolan Show could cost you 7p a minute
Callers are being charged up to 7p a minute to contact BBC Northern Ireland's flagship radio programmes, it has emerged.
The previously "hidden" tariff applies to anyone phoning the likes of The Nolan Show and Talkback.
An Ofcom ruling means the publicly-funded broadcaster must now flag up the cost of calls to listeners.
The BBC said it does not charge people for getting in touch.
It said the cost instead resulted from phone companies charging their customers for making calls.
However, the corporation has been criticised for not making callers aware of the charge before Ofcom stepped in.
Jonathan Isaby, chief executive of the TaxPayers' Alliance, said the BBC needed to be more open with its audience.
"Licence fee payers will be annoyed that these fees were hidden before this ruling," he said.
"Transparency must be at the heart of everything the BBC does."
In recent days, programmes like Talkback, The Nolan Show and Gardeners' Corner have opened with a warning that all calls will be charged at up to 7p a minute. The charge was even queried by Stephen Nolan during his show yesterday.
After being contacted by this newspaper, BBC NI said it had been told to be more specific about charges by Ofcom.
The communications regulator has stepped in amid claims that people were confused about charges to TV and radio shows.
Most TV programmes provided pricing information about taking part in phone votes based on using a BT landline.
However, since most people use their mobiles, calls can cost much more.
As a result, consumers are in the dark that they can be charged up to £2 a minute to take part in some TV and radio programmes.
Since July 1, TV companies have to state how much they will take from every call cost as a "service charge".
This will be capped at 7p a minute for calls to 084 numbers - which the BBC uses.
It costs 13p a minute for 087 numbers and £3.60 a minute for 09 numbers commonly used on TV programme phone votes.
A BBC NI spokesperson said: "A new tariff structure for 0845 numbers was introduced by Ofcom at the start of July 2015.
"These changes also required broadcasters to provide their audiences with more specific pricing information." The BBC pointed out that it does not receive any proceeds from phone charges.
"We make use of a single contact number - 08459 555678 - for all BBC Northern Ireland programmes," it added.
"The BBC does not charge people for getting in touch with its programmes. Call costs will reflect the contract that people have with their own service provider.
"Since July 1 2015, calls are charged at a fixed rate plus the access charge that a caller's provider charges."
BBC NI said it was considering switching to an 03 prefix, which is free in call packages. Many other BBC regions have already completed this switch.
BBC NI added: "We want to make it as cheap and simple as possible for people to get in touch with us and are exploring the options around moving to an 03 based number for all local programmes.
"The BBC continues to weigh up the trade-off of the cost to the caller (individually) versus the cost to the BBC (and hence licence fee payers as a whole) of using various call cost models (eg 03, 0845, 0800 etc)."