Up to 17,000 customers have been caught up in a billing error by their energy company.
SSE Airtricity seems to have overcharged some, and undercharged others.
According to the Irish Independent one case involved an estimated bill of €287 for a customer who has a smart meter.
It quotes a spokesperson for SSE Airtricity as saying the firm is contacting all affected customers directly and the impact will be 'cost-neutralised' through re-billing.