Brexit tariff implication

It depends on the specifics of the Brexit negotiations. Assuming that the UK does leave the existing EU Customs Union, it will have the right to set its own customs tariff; indeed, as an individual “free-standing” member of the World Trade Organisation, it will be obliged to do so. This gives the UK the capability to set rates of duty for goods imported into the UK from all external countries. These could be set at similar levels to the present, or higher or lower (within WTO regulations).