Our major telcos will soon be sharing information with each other in a bid to combat international scammers.
The Telecommunications Forum has released its draft code of practice that Spark, Vodafone and 2degrees will use.
Chief executive Geoff Thorn says it is not as easy as putting a block on the number a scammer uses.
"The scammers are actually getting very sophisticated systems - the number that comes up on the phone might actually look legitimate, so the industry has to be careful about which numbers it blocks."
The proposal is currently out for consultation, before it's finalised in July.
"What we're doing now is turning an informal process into a formal one and extending the use of that information to include third parties, where that's appropriate. If we get the information, the industry can actually take action to stop it."
Third party organisations include police and NetSafe.