De jure | De facto

Northern Ireland would de jure be in the UK’s customs territory but de facto in the European Union’s,” one diplomatic source said of the tentative agreement.”(the Guardian)

de jure
/deɪ ˈjʊəreɪ,diː ˈdʒʊəri/
1. adverb .  according to rightful entitlement or claim; by right.
by right, rightfullylegally, according to the law
2 adjective . existing or holding a specified position by legal right.
de facto
/deɪ ˈfaktəʊ/
1. adverb . in fact, whether by right or not.
“the country was de facto divided between two states”
in practice, in effect, in fact, in reality, reallyactually, in actuality