A lack of volunteers and an increase in demand has forced Samaritans Wellington to redirect some calls overseas.
The service provides confidential emotional support for people experiencing depression distress or suicidal feelings.
Samaritans Wellington operations committee chair Bernadine Reid said the service did not have the staff to cope, so callers were being connected with Samaritan groups in Perth or Launceston, Tasmania.
People can call Samaritans Wellington from anywhere in New Zealand, 24/7, she said.
But Ms Reid said that service was in jeopardy until it connected with the Australian groups in January this year.
She said it teamed up so the three could ensure there were people on every shift, but even then they were struggling to cope.
"We're seeing an increase definitely in the number of calls we're handling and the number of actual people we're speaking to, but at the moment we're really struggling to make sure that among the three centres we are covering every shift."
When the lines were busy some people who were redialling may not be in desperate need of help or in an emergency situation, but there was no way of knowing that for sure, said Ms Reid.
"We've got the technology now with Australia to start analysing what's happening on the phones and we're not picking up half the calls that are made to our lines at the moment.
"So we've got a sense of urgency getting more people covering the roster at all times. Our minimum thing is to make sure we have two [staff], in any one centre.
"As a minimum we're trying to say 'well at least there'll be two people if not in Perth, they'll be in Launceston or Wellington', but ideally there will be two in each centre.
Ms Reid said it was difficult to get volunteers because once a month they had to do a slot between 11pm and 7am, but by connecting with Perth and Tasmania, that shift was able to be covered.
She said they asked volunteers to stay a minimum of two years because of the effort that went into training them, but many did not last that long, as people's lives could change so quickly now.
The centres have taken a collaborative approach to ensure the same high standards are in place for any caller, said Ms Reid.
"We try our best to make the service the best it can be for the people who call and we're reasonably confident that the people who are desperate don't actually care whether it's Australia or New Zealand, it's more about the person who answers and gives them a sense that 'this person is going to listen to me'."
Between the three call centres, half the calls could not be answered because there was such a high demand for the service, which meant people who really needed their support were missing out.
"If the lines are busy they may redial, but until we get the service going so efficiently that all calls get answered within a few seconds, then we don't know if it's not an emergency situation and you can't guarantee that (it's not) and that's just the time that someone who is in a desperate situation is trying to get through."
Samaritans: 0800 726 666 (available 24/7)