Communications and IT minister Steven Joyce has called on telcos to sign a code governing 111 calls "as a matter of urgency", following outages on the system last month.
Joyce says the impact of the recent Telecom network outages has highlighted the need for agreed standards for 111.
See also: 111 failure exposes Telecom's POTS problem
"I am calling on telecommunications carriers to sign up to the Emergency Calling Code as a matter of urgency," Joyce said in a statement today.
The code, developed by the Telecommunications Carriers' Forum, includes input from government. It is a legally binding document and carriers can sign up whether they are a member of the forum or not.
"The code provides a good starting point for ensuring the effective delivery of emergency calls by providing minimum standards," says Joyce.
He says a voluntary code is preferable to regulation but the government is prepared to act if necessary.
"I also call upon mobile network operators to complete a formal arrangement for emergency roaming between their networks, using SOS mode," he said. Roaming failed for some users during the outage.
SOS mode enables mobile phones to use alternative networks for emergency calling when they are unable to access their own network for technical reasons.
Joyce added that officials are actively engaged with the Analysys Mason independent review of recent outages of Telecom's XT mobile network and Telecom's internal investigation of the fault in the Papatoetoe exchange which affected 111 on 26 February.