Lifeline is training up 100 new volunteers to cope with complicated mental health calls over the holiday period.
It's also hiring extra full-time staff.
Lifeline executive director Glenda Schnell said while there was no spike in calls over the Christmas period, the calls were often more difficult.
"We know that over Christmas people have a significantly difficult time.
"People call us because they're lonely and they're reminded of some people that might have been lost or some difficult times that they're facing.
"We also know that many services go on leave and during that time when other services go on leave, people phone us."
The new volunteers have been trained to handle these complex calls. Ms Schnell said they were well supported by team leaders.
She wanted people to be kind to themselves and each other throughout the holidays.
"Be aware if somebody else looks like perhaps they might be struggling or you know they have something that's on their mind and be kind to one another,
"Not everybody has a family and support systems around them so please be kind to strangers and other people who may not know quite so well."
Where to get help:
Need to Talk? Free call or text 1737 any time to speak to a trained counsellor, for any reason.
Lifeline: 0800 543 354 or text HELP to 4357
Suicide Crisis Helpline: 0508 828 865 / 0508 TAUTOKO (24/7). This is a service for people who may be thinking about suicide, or those who are concerned about family or friends.
Depression Helpline: 0800 111 757 (24/7)
Samaritans: 0800 726 666 (24/7)
Youthline: 0800 376 633 (24/7) or free text 234 (8am-12am), or email firstname.lastname@example.org
What's Up: online chat (7pm-10pm) or 0800 WHATSUP / 0800 9428 787 children's helpline (1pm-10pm weekdays, 3pm-10pm weekends)
Kidsline (ages 5-18): 0800 543 754 (24/7)
Rural Support Trust Helpline: 0800 787 254
Healthline: 0800 611 116
Rainbow Youth: (09) 376 4155