I stand to be corrected but if I have a parcel containing several pedals sent from London to my mate in Northern Ireland, there will be no import charges as both areas are within the UK.
I could then then drive for a couple of hours from the Republic of Ireland to my mate in N.I., pick up the parcel and travel back to the Republic, pedals in hand, without the imposition of taxes, as there is free movement of goods between both jurisdictions and all the above is quite legal.