There is no standard for clearing times between Ireland and UK. There are differing arrangements between different banks, and there are different clearing times depending upon whether the cheque is drawn on a London office of a major bank or an out-of-town branch of a non-clearing bank. Typical time is about 4-5 days, but can be longer. An Irish bank may give you credit for it in 4-5 days, but they will reserve the right to recover from your account if it bounces back many days later