The general manager of Centrelink has admitted his department has "made some mistakes" in recent times, but partly blamed the situation on "antiquated" computer systems which are relics of the 1980s.

Hank Jongen appeared on ABC radio in Perth on Wednesday, being interviewed by the host and taking questions from callers. In the wake of the 'robo-debt' automated debt recovery debacle -- where some clients received debts for a time they weren't even on Centrelink, others were told to pay debts even if they disputed it, and many claimed the debt notices they received are incorrect, too high, or just plain false -- Centrelink has been slammed by clients and community groups as well as Labor and the Greens.

Despite the Commonwealth Ombudsman launching an investigation, and a Senate report recommending the system be suspended until fixed and all debts be re-assessed immediately, human services minister Alan Tudge maintained everything is working well. On radio, however, Jongen admitted his department had failed in some respects.

"I understand the department has a goal of 85 percent customer satisfaction... without being unkind to you personally, you've got nowhere near that in recent years," said host Geoff Hutchison.

"That's true," Jongen replied.

The Centrelink general manager explained that the department had been "putting in a massive amount of effort to maintain as high a level of customer service as we can", before again admitting errors.

"We've made some mistakes, I have to say, with the online letters system," Jongen said.

"The initial advice we sent to customers could have been better, and the system which enabled people to resolve those issues could have been better. We work hard to remedy errors that occur like that."