However, the contract could run for a shorter period due to the complication of a new Lottery licence being awarded in November.
The eventual winner of the 20-year licence has the option not to continue with the contract after the licence comes into effect, although when this will happen is unclear. However, the contract can be extended for a maximum period of five years with its agreement.
PR is currently handled by Irish agency Wilson Hartnell, which has worked with the National Lottery since its launch in 1987.
The value of the contract is defined by the tender as between €350,000 and €1.75 million.
The brief covers corporate PR, consumer strategy, product activation, event management, social media and media relations across the various games that the company runs in Ireland.
The current operator of the Lottery is An Post, the postal service. An Post National Lottery Company is responsible for a number of Lottery games including twice-weekly Lotto draws and associated games, EuroMillions, Daily Million, TellyBingo, TV game shows, Millionaire Raffle and a range of scratch card games.
The company will prepare a shortlist of at least five agencies, depending on the number of applications, and invite them to tender.