Today Munster Rugby also announced a novel initiative whereby the person who purchases the 20,011th ticket will win a hospitality package to the upcoming Munster v London Irish Heineken Cup game.
The hospitality package includes two category A tickets, a three-course pre-match meal and admittance to the official post-match reception.
Munster Rugby are urging people to support their interprovincial derby match against Ulster this weekend, and the three worthy charities - Suicide Aware, TLC4CF (Cystic Fibrosis) and UNICEF.
Mick O'Driscoll, one of the Munster players closely involved in the initiative, said: "Having a formal structure to support three charities this season has helped both the players and the organisation to make a real difference, and should do for future seasons.
"I would like to thank our supporters again for rising to the challenge in supporting this game and our charities in such high numbers.
"Please make it a really special day and donate a euro to the volunteers collecting as you leave Thomond Park."
Munster v Ulster tickets are available to purchase online here, and from the following outlets:
Cork (Tramore Road) and Limerick (Thomond Park) Ticket Offices
Munster Rugby Stores in Cork (Maylor Street) and Limerick (O'Connell Street)
You can also ring the 24-hour ticket line (0818719300) and tickets will be on sale at Thomond Park on match night.
Family packs are on offer for only €50 (two adults and two children) and terrace tickets are available to purchase for €22.