One in four phone calls to the Australian Tax Office (ATO) are dumped immediately.

The technique allows the ATO to report lower average wait times but critics say the system doesn’t pass the pub test.

Customers who called for assistance received an automated message which told them the ATO was experiencing peak demand and it was unable to take calls.

That message has been played more than a million times so far this financial year.

The ATO has admitted those calls have not been factored into the average wait times it makes public.

The agency said in a statement call blocking is used reservedly and intermittently to maintain client wait times at acceptable levels.

Callers have responded to the findings and deemed it not good enough.

“To not be able to get through on the phone is not only frustrating but it could cost people money,” Gerard Brody from the Consumers’ Federation of Australia said.

“I don’t think that kind of customer service would be acceptable for any corporate or any small business for that matter,” Council of Small Business Organisations Australia chief executive Luke Achterstraat said.

The ATO is not the only government agency facing this criticism.

One in six callers to Medicare and Centrelink lines don’t make it past a recorded message.