Kiwis now have the option of using their smartphones in lieu of a home phone under a new service offered by Woosh.
The Woosh Unzipped service links iPhone or Android smartphones to calling networks via an app, which can then make free local calls.
National calls cost 13 cents a minute and mobile calls 23 cents.
Inbound calls are routed through the modem to the smartphone. The calls won't count toward data caps, although calls made on other VoIP software will.
Woosh Unzipped plans cost $68 for 10GB a month, 40GB for $73 and 80GB for $94.
In comparison, Vodafone's 20GB naked broadband plan costs $75-85 a month, TelstraClear offers 20GB for $55 and Orcon offers a landline-free 30GB plan from $75.
Richard Fry, Woosh GM of operations, said high calling rates from mobiles meant many people switch to their landline when they are in the house, which the Woosh Unzipped plans would put an end to.
IDC telecommunications analyst Glen Saunders told Fairfax that Woosh Unzipped simplified the free-calling services that many people were already accessing through programmes like Skype and Viber.