Six companies have been fined nearly half a million pounds for using text messages to scam consumers.

The premium rate watchdog ICSTIS fined the six overseas-based companies for sending unsolicited text messages offering prizes to consumers who called premium rate numbers.

The six overseas-based companies, Vertical Media Ltd, Fast Way Holdings Ltd, Litmus Ltd, Indiano Communications, Greenbay Ltd and Quartel Ltd, were fined £75,000 each for breaching the ICSTIS Code of Practice. The companies have also been barred from offering services in the UK.

The companies sent the text messages and also made unsolicited phone calls using automated calling equipment, which would ring once to leave 'missed calls' on mobile phones.

The aim was to entice people into calling premium rate numbers costing up to £1.50 per minute to claim prizes. According to ICSTIS, these either didn't exist or, at most, were much less than what was promised. For example, a large cash prize would be offered but, at best, the prize would turn out to be holiday vouchers with very restrictive clauses.

ICSTIS criticised the four network operators, Intelliplus Group, Redstone Communications, Switch Call and Ventelo for allowing the companies to rent lines.

"This was a serious problem and involves a lot of money. We had some agreement with most network operators last year to end this. So we are disappointed because we feel these network operators have not acted as we expected," said an ICSTIS representative.

However, the six fined companies have appointed another UK company, Smile Telecom based in Bury, to act as their agent. Smile Telecom has been asked by ICSTIS to refund consumers of the six companies.

ICSTIS said the company has refused to do this unless requested to do so by its six clients.