Plans to reduce the need for face-to-face government services by improving confusing online offerings are to be announced on Tuesday.
The Government Digital Strategy report, seen by the BBC, admitted that most people rarely use online government services.
Services which handle more than 100,000 transactions per year are to be completely overhauled.
The government expects the changes to save up to ã1.8bn a year by 2015.
However, the costs of implementing the changes have not yet been outlined.
A business case will be made for each of these services, a Cabinet Office spokesman said.
So we won't be in a position to know costs until those cases have been assessed. The services will be identified and published in the departmental digital strategies alongside detailed delivery plans in December.
The report said that the average cost of an hour of government interaction costs the average citizen ã14.70.
If just half an hour were saved by digitising every transaction currently completed offline, the document stated, the total savings to the economy could therefore be around ã1.8bn.
Redesigns of the busiest services - including HM Revenue & Customs and the Department for Work and Pensions - will begin in April 2013, the document said, with completion predicted for March 2015.
New or redesigned sites launching after April 2014 will be subject to set standards for consistent design and usability.
All must offer application programming interfaces (APIs) - which will allow third-parties to create useful tools and services, a similar approach to that of Facebook and Twitter.
'Costly for government'
The government classes transactions as anything involving sharing information, requesting services, buying goods, asking for permission, or paying money.
It is estimated that more than 1.5 billion transactions of this type are made every year - with the majority being done either face-to-face or over the telephone.
In 2011, more than 150 million calls in 2011 were classed as avoidable and costly for government.
A study of local councils put the cost of face-to-face transactions at ã8.62, transactions via telephone at ã2.83 - but only 15p for transactions via a website.
While millions in the UK have taken to carrying out key tasks online - such as shopping and banking - relatively few have used the web for needs involving government.
Most government transactions fall far short of the standard of the best, the report said.
Unlike successful digital services in the private sector, government's online services are not necessarily better or more convenient than other channels, meaning they will not be users' first choice to transact with us.
It blamed a culture of creating digitised versions of pre-digital business processes, as well as outdated methods of data gathering and sharing.
The government hopes that services that can only take place in the real world can still be enhanced.
Driving tests, for example, still require examiners to fill in and file paper forms, adding cost and delay for users that a truly end-to-end digital service could remove.
The Driving Standards Agency is to begin a trial using mobile devices for examiners in order to eliminate paper forms.
