The half-year figure was boosted by another record achievement, with vans notching up 186,404 registrations for January to June.
Truck registrations, meanwhile, continued their upward trend, up by more than 40% in June and by the same for the year to date.
Mike Hawes, SMMT chief executive, said the record half-year CV total was not "a huge surprise" given the van result: "Registrations of vans have been growing strongly for some time as businesses remain confident and the trend for home deliveries increases further.
"The significant rise in truck registrations in June mirrored the sector's performance in the year so far, while once again it was the heavier vehicles in van, artic and rigid segments that posted the largest rises."
Meanwhile, the bus and coach sector also posted exceptional results for the first six months of 2015, according to SMMT figures.
Registrations were up by more than 17% to 4,679 units, compared to the same period last year. The month of June saw a rise of 32% -- driven by the bus market, which posted a sharp increase of almost 77%.
"Demand for buses and coaches has seen a resurgence in 2015, as the first six months of the year demonstrate continued confidence of UK operators as they invest in their fleets," said Hawes.
"We have seen significant growth in all sectors of the market so far this year – but with the holiday season well underway and demand for coaches easing, it was the bus market that led the way in June."