What happens when the VAT rate changes?
If you are an accountable person, in certain circumstances, you are obliged to issue a valid Value-Added Tax (VAT) invoice. When you issue a VAT invoice, you must apply the rate of VAT in force at the time you issue that invoice.
When making supplies to unregistered persons, you must apply the rate of VAT in force at the time of the supply.
If you account for VAT on the moneys received basis, you must apply the rate of VAT in force at the time of the supply.
Further guidance contains more detailed information on the procedures to be followed when the VAT rate changes.