The drop comes despite a surge in demand, as many British holidaymakers urgently returned from France after the announcement of the reintroduction of quarantine rules on August 15.
Some 11,600 vehicles and 30,000 passengers used the trains the day before.
Eurotunnel Le Shuttle transports vehicles between Folkestone, Kent and Coquelles near Calais.
The overall decrease in the number of travelers has been much smaller than that of airlines such as easyJet, Ryanair and British Airways.
A Getlink spokesperson said: “This success under the circumstances is the result of the incomparable competitive position of the Le Shuttle service, which offers contactless travel from start to finish, as well as the responsiveness of staff to adapt. to the new situation.
Demand in the first eight months of the year decreased by 42% compared to the same period in 2019, due to the impact of the pandemic.
Getlink said it also carried 110,000 trucks last month, down 7% year-over-year.