If I buy something from an EU supplier and I have a VAT receipt is that treated the same for refund purposes as if I had bought it from an Irish supplier?
You should not be charged VAT on EU purchases if you provide your Irish VAT number to the seller. If you were already charged, you may ask seller to refund you the VAT portion and provide them with your VAT number or alternatively claim refund through Revenue via ROS. You may not claim refund on VAT3 but rather under EVR I believe as it's not treated same as bought from Irish supplier. Check Revenue website for more details on claiming refund.