There is no rollover relief available in this case and you need to calculate and pay your CGT liability on the recent sale by the relevant deadlines outlined on the Revenue website. The fact that the proceeds from such a sale might be used to reinvest in no way affects the CGT treatment and does not allow the liability to be deferred or anything like that. If you buy another property and move into it as your Principal Private Residence (PPR) then you have up to 12 months to sell your former PPR on. If you rent it in that 12 month timeframe then there is no CGT issue but longer than that and some portion of the resale gain will be assessable for CGT. If you rent the former PPR out within five years of purchase as an owner occupier then a clawback of stamp duty applies. You should probably get independent, professional advice on the investment and tax aspects of this situation.