The site, which is based on an Oracle/Vignette platform, currently attracts 1.2 million hits a week but Alan Mather, chief executive of the e-delivery team at the Office of the E-Envoy, expects the number to rise steadily over the year.
"We are now looking for pay-back," he said. "I expect people will gradually get interested in the site and at some point a new service or killer app will trigger an upsurge in usage."
He said that, rather than browsing UK Online, users visited the site for a specific purpose. While the tax assessment service has caused a recent surge in usage Mather explained plans to introduce more proactive services to win over yet more citizens.
"Many families receive child benefit but do not take up the associated tax breaks. We could use e-mail to alert them to this. I'd also like to give every individual the opportunity to receive e-mails from a dedicated tax officer," he said.
"We will be using the technology to form partnerships. For example, car drivers need insurance and an MOT certificate to obtain a tax disc - why not issue them all from one place?"
Marc Andreessen, chairman of Loudcloud, the company hosting the portal, said that the infrastructure of the system would enable new ways for people to interact with the site.
"The back end is one system with a single content engine. And we have incorporated XML and Java standards. This means we can adapt it easily and cheaply to present services via digital TV and kiosks. Pilot schemes to offer UK Online via digital TV are already planned," Andreessen said.