Anyone who had received a text scam or had received a suspicious text could forward the text free-of-charge to 7726.
Cert NZ said that generally anyone who had given out personal or financial details in response to a text message was advised to:
• Contact their service provider immediately, such as their bank or IRD. Let them know what's happened and ask what they can do to help. • Change the passwords for any online accounts they think might be at risk and enable two-factor authentication to add an extra layer of security.
Anyone who was concerned about communication they had received about the cost-of-living payment could call Inland Revenue directly on 0800 473 777 to verify it.
National Party deputy leader and finance spokeswoman Nicola Willis said she had received many messages from people who told her they were embarrassed to receive the undeserved money, while some were "very confused".
An Inland Revenue spokesperson acknowledged it was possible people no longer living in New Zealand could get the payment.
"If someone has left the country and hasn't told Inland Revenue they're not living here currently we will have treated them as resident and they may receive the cost-of-living payment."