For most new private residential tenancies in Ireland, a landlord cannot ask for a deposit of more than one month’s rent. They generally cannot require more than one month’s rent in advance either, so the total amount requested at the start is usually capped at two months’ rent. The deposit should be returned when the tenancy ends, subject to lawful deductions such as rent arrears or damage beyond normal wear and tear. If you disagree about a deduction, the RTB’s dispute resolution process can decide the issue based on the tenancy’s individual facts.