Jamie Garwood, of no fixed address, appeared for facts and sentencing in the Launceston Magistrates Court on Friday after pleading guilty to more than 80 charges.

His lawyer, Emily Patch, told Magistrate Ken Stanton her client didn't always comprehend consequences because of the injury sustained during a car crash, but there was no medical evidence to back up the statement.

The 37-year-old's offending started in May last year, which Ms Patch said coincided with his partner relocating to Queensland with their two young children.

Police saw Garwood lose control of his car while driving through Mayfield in May 2018. Garwood told police his young son - who was sitting in the front passenger seat on a booster chair - had egged him on.

When questioned about driving unlicenced, Garwood said he'd just visited his wife in hospital and picked up his son from school because it was raining. The incorrect registration plates were displayed on Garwood's car, so police confiscated them.

Garwood was again caught driving unlicenced and displaying the incorrect plates on his car when he was pulled over for a random breath test at Rocherlea in October.

Between February 11 and 12, Garwood stole Caltex fuel cards from Timberlink Australia's Bell Bay site.

Over the next three months Garwood would rack up more than $2100 of purchases on the cards, buying fuel from the Caltex stations at Bell Bay, George Town and Mount Direction.

From February to March, Garwood went to a number of petrol stations, cut the padlocks off the underground fuel storage tanks, destroyed the tank access, put an electric pump in and siphoned petrol into a tank in his car boot.

He did this on at least seven occasions.

Garwood was remanded to be sentenced on July 26.