Community Law hopes the Ministry of Justice will continue its funding once its current agreement expires in 18 months.
Top-up funding was allocated to the organisation last April after a review of the service in 2013, but the funding is only guaranteed until July 2015.
A spokesperson for the Ministry of Justice says it has no plan yet for what will happen after that date.
Liz Tennet, chief executive of Community Law Centres Aotearoa, says one of the 24 centres in New Zealand has already started charging some of its clients for some services due to funding pressures and the organisation is very reluctant for this to become widespread.
Ms Tennet says their clients cannot afford to pay fees, and the cost of introducing and administering a payments system would cost it more than it achieved in funding.
Community Law helped more than 250,000 last year, she said.