BANKS and utility companies are raking in millions of pounds a year by forcing customers to pay more than expected for using 0845 and 0870 numbers. But The Sunday Times can disclose a simple ploy to get round these rip-offs.

Ofcom, the telecoms regulator, has been inundated with complaints from consumers who believe the companies using these numbers are unnecessarily prolonging calls. It has launched an investigation into the lines as a result.

Ofcom said: “Consumers have become concerned that the revenues that businesses such as call centres may be able to obtain for receiving inbound calls to 0845 and 0870 numbers may provide an incentive for some companies to prolong calls. We are looking at ways to address these concerns.”

Consumers spend more than a £1 billion a year calling 0845 and 0870 numbers. However, there are ways to avoid using these numbers to contact banks.

The codes do not work from overseas, so companies have to give travelling customers a different, local-code number. But these numbers also work from within Britain. Just remove the +44 UK code and add a zero. Barclays customer services, for example, can be reached on 02476 842100.

For local-code numbers for other companies, visit Saynoto0870.com which lists alternative numbers for many well-known firms.

Telecoms companies generally charge between 1p and 5p a minute for 0845 calls, while 0870 numbers can cost 10p a minute. But charges can be even higher from a mobile phone. A peak-time call to an 0845 number on the Orange Everyday 50 tariff costs 12p a minute. The same call to an 0870 number costs 35p a minute.

These so-called “special service” numbers are used by many organisations, including cinemas, hotels and even government departments. However, Ofcom’s figures reveal that banks and utility companies use them the most.

All the Big Four banks’ customer-service help lines are 0845 numbers and some also use 0870 lines. Alliance & Leicester and Lloyds TSB employ the dearer 0870 numbers for certain services, while NatWest only allows customers access to their branches through 0845 lines.

Caroline Harris of NatWest said: “Introducing 0845 numbers meant we could ensure customers could always contact their branch through a local-rate number.” However, she refused to disclose how much the bank makes by using 0845 lines.

Special-service lines were designed to help firms handle high volumes of calls. But the fact that they are money makers has made them popular, whether or not the organisations have high call volumes.

Chris Williams of Uswitch.com, a comparison website, said: “Firms usually get a cut of the call charge from the phone company. On average they make about 2½p a minute from a daytime 0870 call and ½p a minute from an 0845 one. So there is definitely a financial incentive for companies to keep customers on the phone for as long as possible.”

Ofcom wants to introduce maximum 0845 and 0870 charges of 4p and 8p a minute. However, the ceilings will apply only to numbers operated by BT.

A spokesman for Which?, the consumer lobbyist, said: “There is a lot of confusion among customers about how much it costs to call these numbers. One of the main problems is that Ofcom can only introduce price ceilings for BT because it is the dominant telecoms provider. It has no real way of regulating other companies’ charges.”

The numbers are often described as local or national rate, but increased competition means many people pay more to ring an 0845 number than they do to make a local call. This is particularly true for those with plans that include free minutes because there is always a charge for 0845 and 0870 numbers.

Ofcom said: “Discounted call packages mean consumers contacting organisations close to their homes would often be better off calling local numbers rather than 0845 or 0870.”

The regulator is planning to introduce guidelines to help give consumers a clearer idea of 0845 and 0870 charges. But critics believe more should be done to improve clarity, especially as rates vary so much. Some 0870 numbers cost 10p a minute, while others charge only 10p a call.

Williams added: “The cost of the call usually depends on the one or two numbers that follow the initial four digits. However, without contacting your telecoms provider, it is pretty much impossible to know how much you are going to be charged.”