Dunedin social workers are worried people are using donations as a way to dispose of analogue televisions, when they do not really need to get rid of them.
From April 28 next year, the analogue television signal will be switched off in Otago.
Residents will need Freeview, Sky or Telstra Clear to continue watching television after the area goes digital. Dunedin Women's Refuge community outreach worker Amanda Durham said she was worried there was a misconception only new digital televisions would function after the switchover.
''I am worried that families might be facing the additional stress of feeling they have to replace their old televisions, when they really just need to buy a set-top receiver box for about $70.''
Women's Refuge spokeswoman Sue Lytollis said she was concerned some people were donating their old televisions to charities to avoid paying for disposing of them.
Nationwide, her organisation had received an ''influx'' of older analogue television sets.
''We're having to pay $25 to dispose of them ourselves.''
Dunedin City Salvation Army Major Claire Anderson said people were giving large numbers of unwanted televisions to her organisation. She said people would often leave the sets and other unwanted items outside the Salvation Army's warehouse after hours.
It was possible people were wanting to get rid of televisions they thought would no longer work after the digital switchover, she said. However, Dunedin charities usually saw an upsurge in items being handed in at the end of the year with students leaving their flats.
''Just last week we had a flat-load of stuff dropped off but it was all rubbish,'' she said.
The Salvation Army had to bear the cost of disposing of the items, which had cost the Dunedin group $3600 during the past four months.
Freeview general manager Sam Irvine said all that was required to watch digital television was a Freeview set-top box for an existing television.
''You don't need a new TV to watch digital television,'' he said.
''People with more than one TV will need to make sure each one can receive a digital signal.''
Users would be able to use their existing satellite dish or UHF aerial to tune into the digital signal, he said.
However, he advised people with analogue television recorders, such as VCRs or many older DVD players, to consider buying a digital recorder as the analogue devices would not work unless they were plugged into a digital receiver and the television had to be left on the channel they were recording.
Mr Irvine said digital receivers and recorders, as well as new digital televisions, would be widely available at retailers. Further information about the switch was available online at www.freeviewnz.tv .
By Jonathan Chilton-Towle