The stamp duty is payable to Revenue and they affix details of the amount paid on the deed under which you acquired the property. If you have a mortgage then that Deed is with the lending institution, if the property is registered with the Registry of Deeds. If the property is registered in the Land Registry, then they hold the original Deed but they would only release it to a solicitor - because whoever takes it up from them is responsible for its safekeeping.
If Revenue only want a copy of the Deed, then the Land Registry will release a copy to the registered owner on payment of the sum of E25.00.
As always if you have any queries contact the Stamp Duty section of the Revenue for information or your solicitor or accountant for advice.
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