Nearly 40 percent of Australian motorists surveyed for a study admitted to using their mobile phone for work purposes while they were driving.

The Telstra Drive Safe Phone Safe survey found that 39 percent of those surveyed used their mobile phones while driving to, during or from work.

According to the Roads and Traffic Authority NSW website, driving while using a handheld mobile phone in NSW is an offence, with penalties including fines and the loss of three points.

Respondents to Telstra's survey cited reasons such as letting the office know they were running late, organising meetings, and checking their schedule, for why they used their mobile phone while driving.

Murray Bergin, managing director of mobile sales and solutions at Telstra, said it was urging motorists to use their better judgement by not using a handheld mobile while driving.

"Telstra wants motorists to remember to never use a handheld mobile phone while driving, as even a quick conversation can have tragic consequences," Bergin said.

According to a Telstra statement, 14 per cent of respondents also admitted to having sent text messages while driving to, during or from work.

Of those surveyed, 77 percent said they talked for less than five minutes, with 10 percent talking for between six and 20 minutes at a time.