Irish Water customers who fail register for their free allowances- could be faced with an annual bill of over €400.

According to reports in this morning's Sunday Times newspaper, the Commission for Energy Regulation will allow the company to levy a fee of just under €425 on people who don't register for their free household and child allowances.

Irish Water has reported that only 800,000 households (out of 1.65 million households, plus 289,000 unoccupied premises) have registered to date for their free allowances.

The deadline for customers to register their household details has already been pushed back a month until November 30.