Some €1 million worth of Dublin Bus refund tickets remained unclaimed this year, the company has said.
Gráinne Macken, spokeswoman for Dublin Bus, said a recent audit showed that, though up to 75 per cent of refund tickets was claimed in 2005, some €1 million was not reimbursed.
Refund tickets are issued in lieu of cash to passengers who do not have the correct fare when beginning their journey.
"On average about 75 per cent of tickets are claimed at some stage," Ms Macken said. "There are highs and lows during the year - coming up to Christmas you'd have more people claiming their tickets, and the charities would collect them and claim them all together."
Since the auto-fare scheme was introduced in 1999, charities and aid organisations have invited people to donate unwanted refund tickets.
Paddy McGuinness, deputy chief executive of Concern, said the total amount of tickets it claimed from Dublin Bus was "certainly in the thousands". Concern had approached Dublin Bus asking the company to donate the fund to charity, he added, "but they didn't pick up on it. We would be delighted to talk to them."
Mr McGuinness suggested that Dublin Bus installs boxes on its fleet, where passengers could deposit unwanted tickets. "If there's a will, there's a way. We'll provide the way if they have the will. It's very easy to do in many ways."
However, Ms Macken said security and logistical issues would prevent the company from doing this. "There's a security issue, because you could have buses with several hundred euro worth of tickets in the boxes. As well as that, we have more than one thousand buses on the roads, and we would have to install boxes on every one. Who would empty them? Who would count the tickets?"
Dublin Bus argues that the refund ticket fund cannot be donated to charity because it does not belong to the company. When asked if an expiry date could be printed on the tickets, after which the company would be free to distribute the fund, Ms Macken said: "That is an option, but the company would feel that we would still be found fault with, [ in that] we're not giving people a chance to claim their money. We're sensitive to that."
However, under its community support programme, Dublin Bus donates almost €250,000 from the fund to local charities every year.
Ms Macken pointed out that Dublin Bus is the only bus company in Europe to offer passengers full refund receipts. "Maybe we're a victim of our own decision-making," she said.