The tour operator announced on Friday (4 August) the incentives will be awarded to the agent who makes the highest-value booking each week, with winners revealed on its Facebook page and weekly newsletter.
"These vouchers will reward those agents who go above and beyond on our behalf," said head of trade Tom Morgan.
Riviera has already put the vouchers on offer twice this year, once during the peak period and then again at the end of March.
"We’ve already seen some incredible bookings made this year, both for our river cruises and escorted tours, so this incentive gives even more reason to sell Riviera," Morgan added.
The vouchers are not the only trade-specific incentives the tour operator has on offer, as Riviera announced in late May it would host six river cruise fam trips over the summer.