Irish Rail is warning customers who bought tickets from vending machines using certain debit cards recently but were not charged that the due payment will be charged to their account from Monday.

9,000 cards were not charged between the last week of March and the end of May due to a software issue. It affected certain payment cards, but primarily AIB Maestro Debit cards.

The company says no customers would have been overcharged, adding that "the technical issue caused payments not to be processed on certain payment cards only. No overcharging occurred".

The company says the fault has now been rectified and has outlined how it will now charge customers for the tickets purchased.

It says payments will be processed as follows:

• All affected cards with one single transaction over this period will be processed on Monday (10th June)
• All transactions conducted on affected cards from 24th-31st May inclusive will be processed on Monday
• All affected cards with multiple transactions of a cumulative value of less than or equal to €50 will be processed on Monday
• Affected cards with multiple transactions prior to 24th May, the cumulative value of which exceeds €50 over this period, will be charged on a phased basis

Customers with queries are being directed to the Iarnród Éireann Customer Helpline on 1850-885-865

Irish Rail spokesperson Barry Kenny explains.