VoIP service provider Vonage has launched in the UK. The initial consumer voice-over-broadband service will be followed in Spring or Summer, with a Wi-Fi phone that can be used at public hotspots on the same account, and an SME offering that handles up to 50 lines through normal PBX equipment.

Vonage subscribers pay £9.99 per month for unlimited local and national calls, with low international call rates. The user plugs a conventional telephone into an adapter (which Vonage provides) that routes the call onto the user's ISP connection, so both incoming and outgoing calls go over the Internet. For £18.99, a small business package includes a separate dedicated fax number.

In the US, the company has announced plans to offer Wi-Fi handsets, at the Consumer Electronics Show. Users with Wi-Fi can use the Wi-Fi phone instead of the adapter - and also use the same phone, and phone number, at public hotspots. "Most likely these would be offered in the UK around the same time," said Vonage spokesman Jamie Serino. "It's just another piece of equipment."

The F-1000 handset, made by UTStarcom promises to have a 100-hour battery life, and about three hours' talk time, potentially removing one of the biggest barriers to voice over Wi-Fi (see Voice on Wi-Fi? Just say No).

"Users will be able to take their home phone number all over the world, and make and receive calls on it, at hotspots in airports, hotels and coffee shops," said Serino. Apart from the Wi-Fi hotspot costs, these calls would be free or very low in cost. When the user is between hotspots, the incoming calls can either be sent to voicemail or to a mobile phone.

The Vonage service includes free features such as voicemail that can be forwarded to the user's email box as a WAV file, caller ID, and the ability to choose a phone number. Users can also add virtual phone numbers in other areas: for £2.99 a month, a UK user can have a New York phone number allowing people on New York to dial them for a local call rate. "That's one of the few features we charge for," said Serino.

Vonage has not said yet how much the Wi-Fi phone will cost, but the initial cost is likely to be more than a contract cellphone, which mobile operators can subsidise through high call charges: "We might subsidise the handset cost, or not look to make a profit on it, but it will depend on what kind of cost we can acquire the equipment for," said Serino. "Right now we give away a Linksys router, but a Wi-Fi handset will cost more than a Linksys router."

Vonage has no plans to offer enterprise level telephony, but will launch a small-to-medium product in a month or so. "This will be aimed at SMEs with 50 lines or so," said Serino. "The equipment will plug into an existing key system or PBX." There may be a delay in launching this product in the UK, since it involves more equipment and will be going through VAR channels.