The communications regulator has opened a public consultation on proposals to increase stamp prices by as much as 18% in the New Year.
The Commission for Communications (ComReg) is seeking the public's views on An Post's application to increase the prices of postal services for all packages and letters weighing less than 50 grams.
An Post wants to put the price of a stamp for a standard letter for delivery within Ireland up from 55 cents to 65 cents, an 18% increase.
In a statement ComReg said it must "ensure that these price increases proposed by An Post are affordable for postal service users".
The price increase proposals by An Post include:
An 18% increase to the price of the Domestic Stamped Letter from 55 cents to 65 cents.
A 9% increase to the price of Domestic Metered Letter from 54 cents to 60 cents.
A 10% increase to the price for users of Bulk Mail Discount 6 Letter from 41 cents to 45 cents.
The closing date for any submissions to ComReg is January 31st.