BroadbandChoices.co.uk have called on industry regulator Ofcom needs to take action to ensure ISPs give customers correct information when inquiring about changing providers.

But 46 per cent of call centre operators which were called by the comparison site gave incorrect advice when questioned about obtaining a migration authorised code (MAC) concerning moving to a local loop unbundled (LLU) provider.

There are more than three million unbundled telephone lines in the UK and rapidly growing. The process of LLU involves communications providers, such as TalkTalk or Sky, installing their own equipment in telephone exchanges, meaning that they do not have to rely on BT's existing infrastructure.