'Two-tier fees' to call companies, Which? claims
Existing customers are being charged to call a string of banks, insurers and energy companies unlike some new customers, a consumer group has said.
Which? tested 34 businesses and found that 27 of them advertised free 0800 numbers for new customers to call.
Existing customers, including some who may call to complain, were only given these free numbers by six businesses.
These companies argue that costs are kept low and options include emails and call-backs.
Information from regulator Ofcom shows that various number prefixes are charged at different rates to callers. For example, 0845 numbers are typically charged at between 1p and 11.5p per minute, depending on the time of day for landline customers. Some BT customers can avoid these fees by making calls at certain times of day.
Calls from mobile phones to 0845 numbers generally cost between 20p and 41p per minute.
Which? found that 20 companies made their customers call 0845 numbers to complain about bad service or problems with their bills.
However, new customers were invited by many companies to call 0800 numbers which are free from landline telephones, but not from all mobile phones.
"It is unbelievable that companies would add insult to injury by charging their customers a premium to make a complaint," said Richard Lloyd, Which? executive director.
"It is even worse when they offer new customers access to 0800 numbers while leaving loyal customers to pay more.
"We want to see providers being fairer to their existing customers and being more transparent on their call charges, so that people are clear what it will cost before they pick up the phone."
Three businesses highlighted by Which? as having a two-tier charging system have defended their position.
First Direct bank and energy provider Scottish Power said that customers who had to wait on the line were offered the option of a call-back.
The duo, as well as Churchill insurance, said that the use of other 08 numbers meant they could deal with calls from customers quickly and efficiently.
Which? found that five energy companies offered free 0800 numbers to new customers, existing customers and complaints.
They were British Gas, Cooperative Energy, EDF, Npower and Ovo. SSE pledged to offer 0800 numbers for all customer services in the near future.