The security deposit is considered the lawful property of the tenant, until the landlord establishes a right to it.
Tenants are entitled to a refund of the deposit paid at the commencement of the tenancy where there is no rent owing or other charges or taxes (e.g. utility bills, refuge bills, insufficient notice given etc.) in respect of the tenancy and there is no damage to the dwelling beyond normal wear and tear at the end of the tenancy.
Landlords are required to refund the deposit promptly less any deductions in respect of outstanding rent or other charges or taxes and damage in excess of normal wear and tear. If the rent, charges or taxes or the damage amounts to below the value of the deposit then the landlord should return the excess. The onus is on a landlord to show why a deposit should be retained.
If you believe that your landlord is unjustifiably retaining your deposit, you may take a case against your landlord. You can submit an application online by clicking here or call 0818 30 30 37 to request an application form.
A short guide to security deposits can be found here.