The number of subscribers to retail voice over IP (VoIP) services rose by 83 per cent during 2005 according to research from analyst firm, Point Topic.

Subscriptions rose from 10.3 million at the beginning of 2005 to over 18.7 million subscribers worldwide by the end of the year Point Topic said.

Point Topic’s research has also estimated the number of people paying for PC-to-phone calls during 2005 at over 4.7 million. When combined with the retail VoIP total, this increases the overall VoIP paying subscriber totals to just under 24 million, compared with 14.4 million a year previously.

The analyst said that Japan, France and the USA continue to dominate the VoIP market in terms of subscriber numbers. A spokesman from Point Topic explained that the French market’s acceptance of the technology was largely fuelled by the country’s unbundling strategy, while Japan “led in VoIP principally because of a deal Yahoo Japan/Softbank rolled out two years ago which provides VoIP in such a way that the customer doesn’t notice [they are using an alternative technology].”

But other European nations, notably Germany, the Netherlands and Norway had begun to see a significant number of VoIP subscribers by the end of 2005. Many of these markets were reporting strong growth for early 2006. Many markets, especially in the USA and Europe, should see significant growth in VoIP during 2006, Point Topic said.

France is the biggest market in Europe, with over 2.8 million estimated paying VoIP subscribers, not including Skype users. In the UK, BT’s VoIP service had a relatively slow start in 2005 but is, according to Point Topic, doing well in 2006

Retail VoIP numbers more than doubled in the US and Canada during 2005 with the troubled Vonage leading the pack.