NBN CO has released a revised statement for areas losing the copper network in May.
Last week, NBN Co said residents in the first and second release sites had just six months to switch to the NBN.
However a spokesman has confirmed the copper network will only be shut down in the Minnamurra/Kiama Downs first release site, including all existing landline phone, ADSL internet and Telstra cable internet services.
The revision is in line with the original announcement NBN Co's head of product management and industry relations Jim Hassell made last year.
While almost 70 per cent of the residents in Minnamurra and Kiama Downs have already signed up to the NBN, spokesman Darren Rudd urged the remaining 30 per cent to make the change.
"To avoid getting stuck in the last-minute rush, which could mean you end up not having your home phone and internet services working, we'd encourage you to make the switch."
"Even residents who don't use the internet will still need to switch to the NBN if they want to keep using their home phone. This includes community members with special equipment, such as medical and security alarms, which are connected to the home phone."
To switch to the fibre network, residents can contact their current service providers or visit nbnco.com.au/serviceproviders for more options.
The Minnamurra/Kiama Downs site will be among 15 sites nationally to lose their copper services on May 23.
The copper shutdown for the second release site is yet to be announced.