The Public Service Association, New Zealand, says it will be talking to other government departments about the possibility of job losses as they move to put services online.
Cabinet has given the go-ahead for all survey and land title transactions to be lodged electronically, leading to the loss of 112 jobs at Land Information New Zealand.
PSA national secretary Brenda Pilot says the job losses are the most significant in the public sector for some time.
She says the union will be reviewing the government's e-strategy and talking to other departments about the possibility of more job cuts.
Meanwhile, conveyancers and surveyors say the current online system run by Land Information New Zealand needs to be more reliable.
Tim Jones of the New Zealand Law Society Land Titles Committee says the system needs to be more robust as there have been problems with the reliability of the service.
Land Information New Zealand says they are continually fine tuning the service.