Management committee secretary Norma Elsom said the phone service had been down since May 2, when three of telecommunications company Conec2's subsidiaries went into administration.

"I rang Telstra on Thursday to get us converted to them, and they said it would be five to seven business days before we're back on," she said.

"So that's another week."

Staff have been using mobile phones in the meantime.

"A few of the residents have their own individual phone lines through other companies," Mrs Elsom said.

"Other people wanting to ring their mothers for Mother's Day won't be able to get through."

She suspected other Wimmera aged care centres might also be affected by Conec2's issues.

"We originally went with Conec2 because their aim was to get a cheaper rate of calls for aged care businesses," Mrs Elsom said.

"I imagine there would have been others that would have taken them up."

Wimmera businesses Horsham Truck Company, Stawell Steel Fabrications, Hopper Electrics and Horsham's O'Callaghan Parade Veterinary Clinic were also affected by Conec2's administration.

Ferrier Hodgson now controls Conec2 subsidiaries AsiaPAC Communications, iBoss International and One Telecom.

Mrs Elsom said people could email aephome@netconnect.com.au to pass on a Mother's Day wish to a resident on Sunday.