Around 24,000 Electric Ireland customers will receive two bills at once as a result of a billing issue at the utility company.
Electric Ireland blamed the delay on the "complex nature" of implementing the Government's temporary VAT reduction, alongside the issuing of a €200 credit for energy bills.
Electric Ireland said it worked with the appropriate tax and regulatory authorities to make the required amendments to customer bills over a short period of time. Despite this, it said there was a delay in issuing bills to 2% of its customers.
Those customers are now set to receive two bills consecutively.
Electric Ireland, which is a subsidiary of the ESB, currently has around 1.2 million residential customers and 95,000 business customers on the island of Ireland.
"We apologise for any inconvenience this may cause to some customers and we ask that these customers call us on 1800 372 372 if they have any concerns in relation to their bills," a spokesperson said in a statement.
"We will work with them to ensure a solution, including a manageable payment plan, is put in place."
The company also said the cost of energy for the period in question will be normal, with its recently-announced price rise not set to come into effect until 1 August.
