Most writing competitions do charge an entrance fee, and as long it's reasonable, that's understandable. Still, sometimes they're expensive, and they do start to add up if you are entering a few. So, here are two free to enter short story competitions. They are both well known annual competitions and are run by County Councils in Ireland. The deadlines are in late February and early March.
From the Well Short Story Competition 2015 Cork County Library and Arts Service - deadline 20th February 2015. There is a theme of 'Light' and a maximum word count of 2,000. The judges for the 20 shortlisted entries are Claire Kilroy, Declan Meade and Billy O’Callaghan. For further details, rules, and an entry form see here
Molly Keane Creative Writing Award 2015 - deadline Friday 6th March 2015. Maximum word count 2,000. For full details, rules, and the entry form see Waterford City and County Council website here