DIETRA BREEDON, an American living in London, likes to phone her mother in Newport, Virginia, a couple of times a day.

They can speak across the Atlantic as often or as long as they want, but since Breedon starting using a firm called Vonage, the cost will never be more than a monthly fee of £2.99.

“It helps the bank account,” she said. “My father’s happy and my husband’s happy.”

When The Sunday Times called Breedon on her London number last week, she was in South Africa, accompanying her husband on a business trip. But the call to her Mayfair home found her instantly, rerouted to a mobile phone thousands of miles away.

“You just called me on a British number and I’m in South Africa,” said Breedon. “How cool is that?”

Welcome to the wonders of internet telephony, or voice over internet protocol (VoIP) in industry jargon. Proponents claim it offers a tantalising mix of greatly reduced bills and sophisticated new services.

It could also mean the end of the traditional phone bill. If VoIP takes off, paying per-minute charges for individual calls will soon become a thing of the past. At most, customers will pay a monthly service charge — and with some providers even that will disappear.

Niklas Zennström, chief executive of the London- based Skype, is at the most “disruptive” edge of this new technology. He said that telecoms companies used to have their own networks, and routed calls over fixed circuits.

But with the convergence of telecoms and computers, call traffic is moving on to one simple network — the internet. “What happens is that the marginal cost for a voice call is zero,” said Zennström. “You can no longer charge for phone calls. Phone calls are free.”

In only two years Skype has attracted 30m users worldwide who have spent 6.3 billion minutes using the service. For free.

Breedon is one of the first British-based customers of Vonage, the company that has blazed a trail for internet telephony in America.

Whereas Skype appeals to more technically savvy users, happy to make a call on a headset from their computer, Vonage is chasing more traditional business. Although the Vonage service requires a broadband internet connection, customers can plug their conventional phones into an adapter.

“I’m not techy,” said Breedon. “I’m actually quite clueless. I use my regular phone.”

Explore Tech & Web

• Personal Tech

• The Web

• Gadgets & Gaming