The industry is in danger of losing tens of millions of pounds worth of training funding as the spending cut off for the apprenticeship levy looms.
RHA deputy policy director Colin Snape warned delegates at the Microlise Transport Conference that of the £68m the sector had paid into the levy since its launch last year, only £2m had been withdrawn again.
The levy has a 24 month cap on spending money that has been put into it, after which it ceases to be available to employers.
"There's only 11 months left until people paying money into the levy start losing it," he said, "so you need to get in there and you need to start using it.
"One of the reasons people aren't using the levy is because there's a lot of confusion about it."
He urged any employers struggling to use the money, or that didn't understand how to access it, to contact the RHA for help.
Snape also told delegates that the race to employ skilled drivers was heating up as countries accross Europe were struggling to fill vacancies too.
Compared to the RHA's estimated 45,000 driver shortfall, Snape said Poland was short of 100,000 drivers, while Frnace was in need of around 17,000 more.
"We aren't the only people fighting for the few drivers that are about", he warned.