Centrelink’s phone system returned 55m engaged signals last financial year, prompting further criticism that the agency is “in crisis”.

The figure is a dramatic increase on the 29m calls that received a busy signal in 2015-16, and the 22m in 2014-15.

The evidence, which does not include the number of abandoned calls, emerged during Senate estimates on Wednesday evening.

The new secretary of the Department of Human Services, Renée Leon, blamed the significant increase on the uptake of automatic dialling apps on smartphones.



Leon said those apps accounted for roughly 20% of the busy signals recorded by Centrelink.

“That’s not 55m unique calls, our analysis of the telephone data is that in the vicinity of 20% of those are repeat dialling apps that people now have on their smart phones,” Leon said.

“So 55m doesn’t mean there were 55 million people who tried to ring, because many of those were repeat call,” she said.



But Labor jumped on the figures as evidence of an agency “in crisis”.

Labor senator, Lisa Singh, expressed frustrations on behalf of welfare recipients to the departmental officials.

“I’m sure you can appreciate how frustrating this must be for millions of Australians trying to get through that get that busy signal,” she said.

“What’s more concerning though is that each year, year-on-year, the number is getting bigger and bigger by the millions.”

The shadow social services minister, Jenny Macklin, issued a statement describing the figures as “shocking”.

“This simply isn’t good enough. Centrelink is under-resourced and understaffed,” Macklin said. “Centrelink needs permanent, full-time staff, who are qualified and familiar with the often complex issues facing Australians who require income support.”

Greens senator Rachel Siewert said the 55m busy signals represented a “lot of frustrated people who may be exasperated and struggling”.

“On top of this 55m there were nearly 7m abandoned calls,” Siewert said. “This isn’t surprising because when you get through you have to wait for long periods before you speak to a human being.”

The government recently announced plans to introduce private workers from multinational outsourcing giant Serco to the Centrelink call centre.

The human services minister, Alan Tudge, said the 250 staff would help relieve pressure on the centre and reduce call wait times.

“I am not going to put a figure in terms of what that might reduce the minutes by, but that, in concert with some of the other things that we are doing, will hopefully see a demonstrable difference by next year whereby people won’t have to wait for as long,” Tudge told the ABC last week.

“I am not promising to change the world here but, nevertheless, I hear what people are saying about waiting too long and we are addressing it.”