Use EU when you mean EU member states: EU countries, EU businesses, EU consumers, goods exported from the EU, EU VAT numbers.
Defnyddiwch yr UE wrth sôn am aelod-wladwriaethau'r UE: Gwledydd yr UE, busnesau'r UE, defnyddwyr yr UE, nwyddau a allforir o'r UE, rhifau TAW'r UE.