Stamps will become more expensive from 21 July, with An Post increasing the rates for postal services on both domestic and international letters.
The standard domestic letter rate for items up to 100g posted within Ireland will increase from €0.70 to €0.72, while the standard international letter rate up to 100g will increase from €1.05 to €1.10.
This will be the second increase in just over a year.
Last July An Post raised the cost for items up to 100g within Ireland by €0.02, while the standard international letter rate was increased by €0.05.
An Post says that, despite the latest increase, postage rates here are among the lowest in the European Union, with the average letter postal rate in the bloc €0.93.
It added that a wide range of discount options are available to businesses, and significant discount options continue for Ceadúnas licence and bulk-mail services.
The new Ceadúnas rate for Standard Post letters up to 100g will be €0.70.
However, An Post also highlighted that the "significant cost" of supporting its "Universal Service Obligation (USO) will require attention".
The USO requires An Post to provide daily collection and delivery service to all areas of the country for a uniform tariff.
Last year the cost of maintaining the USO was €32.3m.
