Pssst! Vonage Holdings Corp. has discreetly launched its U.K. service. The voice-over-broadband specialist has not, though, officially announced the offering -- which is unusual for a company that's been particularly prolific at pumping out press releases (check out the firm's press center).

At present the VOIP service, which launched on December 28, is available only through the company's new U.K. Website, with customer enquiries being handled by the firm's U.S. call center.

However, the service provider has lined up some high-profile High Street partners and plans a national advertising blitz in the coming weeks (see Vonage Sets UK Launch Date).

The residential package, aimed at the U.K.'s 5 million-plus broadband users, allows unlimited national and local calls to fixed-line numbers throughout the U.K. and Ireland for £9.99 (US$18.76) per month. This compares with the $24.99 monthly charge for unlimited local and long-distance calls offered to customers in the U.S. and Canada, where Vonage now has more than 400,000 subscribers.

Calls to U.K. mobile numbers are 15 pence (28 cents) per minute during the day, 10 pence (19 cents) in the evening, and 5 pence (9 cents) at the weekend.

The small-business tariff is £18.99 ($35.64) per month, compared with $49.99 for the equivalent North American package.

Vonage provides the adapter that connects regular telephones to the customer's broadband modem for free, while services such as voicemail, call waiting, call diversion, and caller ID are also free. Customers nominate an alternative telephone number to which their calls can be diverted when their broadband connection is down. Emergency service calls are automatically routed by the Vonage system to the standard national emergency operators.

International calls cost extra and are charged by the minute. Calls to the U.S. are 2 pence (3 cents) per minute, and most Western European destinations are between 2 pence and 4 pence per minute.

Vonage's U.K. adventure will be closely watched, as the cut-throat British market is already awash with low-cost traditional telephony packages. Vonage always knew the U.K. was a gamble and planned to keep its setup costs low (see Vonage Plans Q4 Launch in UK).

If the VOIP upstart can build a financially successful U.K. business (the company hasn't revealed any business targets), that could herald the launch of voice-over-broadband services in Europe's other highly competitive markets, such as Spain, France, and the Scandinavian countries.

So will Vonage launch elsewhere in Europe? Vonage is still considering a service launch in Switzerland, according to a spokesman who says there is no fixed timeframe for such a move. He adds that "expanding into the Pacific Rim region" is also under consideration. Singapore is thought to be the most likely target market.

— Ray Le Maistre, International News Editor, Light Reading