State government child protection reporting systems are being clogged by thousands of reports that aren't serious enough for them to act on, a commission has heard.
NSW Department of Family Services secretary Michael Coutts-Trotter says the department received 120,000 calls last year that did not meet the "risk of significant harm" threshold.
"In effort terms, that's about 100 child protection caseworkers working in intake, taking reports we don't act on as a statutory agency," he told the Royal Commission into Institutional Responses to Child Sexual Abuse on Wednesday.
Mr Coutts-Trotter said the department received 150,000 reports that met the threshold, in respect to 75,000 children last year.
The royal commission heard Queensland also had a similar problem with large volumes of calls.
"The effect of there being a large number of reports that don't meet the threshold means... that children who are the subject of those allegations may receive less priority, attention, than otherwise," Counsel assisting Gail Furness SC said.
"That's the risk," Mr Coutts Trotter replied.
The hearing has in part been investigating how the state, territory and Commonwealth governments have so far responded to the royal commission's work.
It heard COAG had last year made a commitment to roll out reportable conduct schemes similar to NSW's, which requires any abuse or assault of a child to be reported to an ombudsman, nationwide.
The scheme also includes audits of how employers respond to allegations.
Reportable conduct arrangements are about to come into force in Victoria and ACT, the royal commission heard.
