People using the little icons which denote happy, sad or other emotions in their text messages could be racking up big bills, the BBC has learned.

Consumer website MoneySavingExpert has received a large number of complaints about the issue.

It seems to affect older models of phones, including some Samsung and Apple handsets.

In Scotland, a woman ran up bills totalling over 1,000 after adding emoticons to text messages.

The issue revolves around how the handset interprets the icons, known as emoticons or emojis.

In some cases, especially on older handsets, the emoticons are converted into MMS (multi-media service) messages which can cost up to 40p each depending on the network.

MoneySavingExpert also found that, in some cases, users creating their own icons from full-stops, commas and brackets found they were converted into emoticons, running up the same charges.

"We have seen many complaints from our users who have racked up huge bills for sending what they thought were text messages," Guy Anker, managing editor, told the BBC.

Paula Cochrane told the Daily Record that she had no idea that the emoticons were being charged as picture messages.

She complained to her provider EE and also plans to take her case to the Scottish ombudsman, an independent organisation that settles consumer complaints.

"There are a number of factors which can affect whether customers are charged for sending an emoji usually by the settings on the handset and so it is a manufacturer - rather than a network - issue," an EE spokesperson told the BBC.

BBC News