Placing restrictions on EU citizens' right to work in the UK would not require new infrastructure at the Irish border, an independent report has said.
The Migration Advisory Committee (MAC) has been examining the role of EU workers in the UK.
It said that any new restrictions can be enforced at the workplace rather than the border.
But, it warned that differences in customs rules or regulatory standards "pose a much more serious problem".
The report notes that the UK government has committed to retaining the Common Travel Area (CTA).
This is the arrangement that allows British and Irish citizens the right to travel to and work in each other's jurisdictions.
In the future, citizens of other EU countries may have the the right to reside and work in the Republic of Ireland but not in Northern Ireland.
However, the MAC said that would not create a "new category of problem" as there are already likely to be some non-EU citizens with the right to work in Ireland but not the UK.
"Enforcement of rights to work do not require checks for people crossing the Irish border as these rights are not verified at the border, but in the workplace via employment checks," the report said.
It also also said that if visa-free travel for EU citizens coming to the UK remains there will be "no danger" of Northern Ireland being used as an illegal immigration "back door".
It added that there are already a "large number" of citizens of non-EU countries who come to the UK without the need for a visa but who do not have the right to work.