An Post has announced a rise in the price of an international stamp as well as increased prices for some large envelopes and parcels.
But the cost of a stamp for sending a letter or card in Ireland is staying at €1, An Post said.
An Post said its rates are in line with comparable tariffs across Europe.
The new rates will come into operation on Monday February 25.
In a statement today, An Post said that rates for large envelopes, packets and some parcels within Ireland are increasing by an average of 5.9%. However some postage rates will fall.
International postal rates are increasing by an average of 7% with the cost of sending an international letter increasing from €1.50 to €1.70.
An Post also said there will be no changes at this time to the rates for its bulk mail discount services for large volume mailers.
However, within the next few months, it said it will introduce new bulk mail discount services to better serve the changing needs of customers.
It also said that the price of its Redirection service, which is used by people moving address, is being reduced "significantly" with the introduction of a one-month service option.
The company's MailMinder rates are also being reduced to encourage customers to have all their post stored securely at the local delivery unit while they are away on holidays.
"The increases in rates for international postage and larger items are reflective of the increasing costs of sending mail items worldwide and of delivering to every home and business in Ireland every working day", commented Garrett Bridgeman, Managing Director of Mails & Parcels at An Post.
He said that where rates are being increased, the level of increase has been kept to the absolute minimum and against a backdrop where there has been decline of almost 50% in transactional mail over the past decade.
"The increases are being implemented in conjunction with a major business transformation and cost reduction programme encompassing every part of An Post and our policy of fair, cost-reflective and simplified pricing for products and services," he added.