More than 7000 Otago homes may not be able to be converted to digital television in time for the switchover from the analogue network.
Dunedin electronics retailer Dick Smith confirmed its New Zealand stock of UHF aerials was almost depleted.
''People are definitely going digital, both in Otago and across the South Island,'' Going Digital national manager Greg Harford said.
''I'm recommending people take action now to go digital.
''When Hawkes Bay went digital last year, there were people who waited until the last minute and then had to go without TV for a time, because installers were fully booked.''
The latest Going Digital figures show there are 7155 Otago households with televisions that will no longer function when analogue television is switched off.
''After April 28, everyone in Otago who wants to watch TV will need to have Freeview, Sky or Igloo,'' Mr Harford said.
''You don't need a new TV to go digital, but everyone will need a TV with Freeview built in or the right set-top box, together with a UHF aerial or satellite dish. I'd also advise people to check the equipment they've already got.
''There are a lot of people who already have the aerial they need.''
Freeview Satellite is available to all homes and can be picked up with a satellite dish connected to a Freeview Satellite receiver, while FreeviewHD is available to 86% of homes and can be picked up with a UHF aerial connected to a FreeviewHD receiver.
''Right up until 28 April, Going Digital staff will be out and about in Otago talking with people and discussing what needs to be done to make sure everyone can keep watching TV,'' Mr Harford said.
The old analogue signal is being switched off to to make the spectrum available for other purposes, such as wireless broadband, data and telecommunications services.