BT has received "a number" of complaints from Welsh-speaking customers who had been told by pager operators that they were no longer allowed to communicate in Welsh.
The change in policy, a BT spokesman said, was made in February this year. BT operators were instructed not to transmit messages in any language they did not understand.
So, staff might be quite familiar with French words such as "bon soir" (goodnight) or Spanish words like "adios" (goodbye) and be happy to include them in pager messages.
But the Welsh equivalents - nos da (goodnight) and da boch (farewell) - may well be not be so familiar, and BT operators would be within their rights to refuse to communicate them.
"We did take messages in Welsh at one time but we stopped doing that simply because the operators taking those messages were English and didn't understand them," said Chris Orum, BT spokesman in Cardiff.
'Obscene or depraved'
"For all they knew, they could have been sending out obscene or depraved material," he said.
"We still have people calling up wanting to send messages in Welsh. We have had complaints from pressure groups and customers and BT is now looking into ways of resolving that."
And language lobby groups assure BT will be held to its word.
Dafydd Morgan Lewis of Cymdeithas yr Iaith Gymraeg, the Welsh Language Society, said: "It is a cause for concern. We have received a lot of complaints about this.
"I think it is the responsibility of British Telecom to provide a fully bilingual service to customers in Wales," he said.
He said Cymdeithas had met BT in February to discuss the issue.
The statutory body responsible for promoting the language, the Welsh Language Board, also confirmed that it had been in discussions with BT over the matter.
Welsh is spoken by just over half a million people in Wales, accounting for 18.7% of the Welsh population.
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British Telecom
Welsh Language Board
Cymdeithas yr iath Gymraeg (The Welsh Language Society)
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