The ILB Championships are played each year starting in late April and culminating in the ILB Championship Finals week which is always played in the week culminating in the August Bank Holiday Monday.  The semi finals are played on Monday through Thursday evening and the finals on Friday evening and all day Saturday.  The Sunday is rarely used but is reserved in case of weather causing serious disruption to the week.

There are two sets of Championships the Senior and the Junior.  The Senior Championships are part 1 of the IBA & IWBA National Championships and the various winners go forward to the respective National Championships each year. As the IBA and IWBA are single gender organisations only men can play in the IBA Championships and ladies in the IWBA championships.   Should they be successful in the national championships  they will go forward the following year to represent Ireland in the British Isles Bowling Council (BIBC) and BIWBC championships respectively

The junior championships are a purely an ILB competition and there are various rules to exclude Senior Bowlers from playing in them.  A Senior Bowler is bowler who is registered in the Premier Division or Division 1 saturday or division 1 Wednesday , or plays regularly in those division.  A junior bowler can enter the senior championships but cannot enter both Senior and Junior in the same year.  The junior championships are open to all junior members irrespective of gender,