A truckie has been caught driving at more than 60km/h above the speed limit in northwestern NSW.

Police say the driver was clocked doing 123km/h in a 60km/h zone on the New England Highway north of Tamworth just after 11am (AEDT) on Wednesday.

The 45-year-old driver was fined $3,267 and banned from driving for six months.

"There is no justification for excessive speeding in any vehicle, especially not in a heavy truck," said acting Traffic and Highway Patrol commander Superintendent Stuart Smith in a statement.

"We will continue to commit plenty of resources to catching and charging any heavy vehicle drivers or operators who break the law and put innocent lives at risk."

The truck has been grounded and will be inspected by Roads and Maritime Services (RMS) staff.