Australians will be able to access government services with a single log-in under a plan to create a "single digital identity" by 2025.

Michael Keenan, the minister in charge of digital services, said face-to-face interactions with government services would be greatly reduced.

"Think of it as a 100-point digital ID check that will unlock access to almost any government agency through a single portal such as a myGov account," Mr Keenan said in a statement.

The minister wants Australia to be a world leader in digital government, with almost all services to be available online by 2025.

Mr Keenan will outline the plan at the National Press Club in Canberra where he will say having 30 different log-ins for government services is not good enough.

"The old ways of doing things, like forcing our customers to do business with us over the counter, must be re-imagined and refined," he will say.

People will need to establish their digital identity once before being able to use it across services.

The first of several pilot programs using a "beta" version of what will be known as myGovID will begin in October.

The initial pilot will enable 100,000 participants to apply for a tax file number online, which Mr Keenan says will reduce processing time to a day, when it currently can take up to a month.

In a pilot starting from March next year, services including student identification and Centrelink will be connected to the digital identity.

Also from March 2019, 100,000 people will be able to use their digital identity to create their My Health Record online.

Mr Keenan says one face-to-face or over-the-counter transaction costs on average about $17 to process, while an online transaction can cost less than 40 cents.

The Human Services department will operate as the gateway between service providers and people.

"This is key to protecting privacy, as the exchange will act as a double blind - service providers will not see any of the user's ID information and identity providers will not know what services each user is accessing," Mr Keenan will say.