Taxation (Cross-border Trade) Bill

Will the Minister confirm that on our current frontiers with the rest of the EU, excise, VAT, general taxation and currency are all different on the other side of the channel or the other side of the border with the Republic of Ireland, and that that all works very smoothly and mainly electronically today? Why do people think there would be a bigger problem if we needed to add another line to the electronic register because there was a customs charge as well?