An Post has applied to the communications regulator for an increase in the price of a basic stamp from the current 48c to 55c from 1 March.
As a result, ComReg has launched a public consultation process before deciding on whether to approve the increase.
ComReg said that the application was for an increase in the standard letter category up to 50g and, if approved, prices for the 50-100g large letter category would come down from 60c to 55c.
In its application, An Post said that by 1 March, it will have been 42 months since prices were last increased.
An Post also pointed to significant cost increases in that period, and further cost increases for wages, energy and fuel over the next 12 months.
