Dublin Airport has said it is writing to around 4,500 customers, who were overcharged for parking during promotional campaigns earlier this year, to refund a total of €350,000.
The issue came to light after a number of customers complained to the Competition and Consumer Protection Commission (CCPC).
Dublin Airport said that during the two promotional campaigns - a 'Holiday Blue Flash Sale' in March and a 'Long Term Car Parking Promotion' in May - a pricing error occurred.
According to the airport, a flat €10 per day rate was applied across all eligible dates, which unintentionally overrode lower off-peak prices.
This resulted in around 4,500 customers being overcharged by a total of €25,000, with individual amounts ranging from €1 to €64.
Dublin Airport said that 90% of customers impacted were overcharged by less than €12, with an average overpayment of roughly €5.90.
It added that once the situation was flagged by the CCPC a full internal review was launched.
Affected customers will be refunded the total cost of their booking and not just the overcharged amount (totalling approximately €350,000) and offered a 20% discount on future car-park bookings as "a goodwill gesture".
Dublin Airport chief executive Kenny Jacobs apologised for the overcharging and said the airport has "put new checks in place to make sure this doesn't happen again".
The CCPC said refunds will be issued directly to consumers within the next five to ten days.
Examples of consumer complaints received by the CCPC included a consumer who reported that the day before the sale, on 9 March, the price for 10 days' parking was €83. However, this rose to €110 for the same dates and duration in the sale. The consumer further informed the CCPC that when the sale ended, the price reverted to €83.
Another consumer told the CCPC they booked parking for a five-day stay during the sale at a cost of €60, and the price for the same parking was €56 after the sale ended.
"We welcome the swift action taken by daa following contact from the CCPC alerting it to potential breaches of consumer protection laws," CCPC Chair Brian McHugh said.
"The CCPC was able to take this action thanks to consumers who took the time to report concerns about misleading sales pricing. All calls to the CCPC helpline are screened for potential breaches of consumer protection law and drive our enforcement and compliance activities," Mr McHugh said.
"The flash sales coincided with the addition of a new competitor in the airport car park market. Active competition among businesses is vital to drive choice, better service and innovation. However, any promotions need to be grounded in real benefits to consumers," he added.
