The party says it will bring in immigration officers to carry out checks of buses and trains crossing between north and south.
Reform has said it would bring in new immigration spot checks at the Irish land border and fine transport firms £10,000 per passenger found to be entering Northern Ireland illegally.
MP Danny Kruger will tell the DUP conference later on Friday that the move aims to stop “illegal and unvetted dangerous criminals” using the border between the Republic of Ireland and Northern Ireland as a backdoor route to the UK.
But he will insist it is “not a border check”.
The party is pledging to bring in immigration officers to carry out spot checks of buses and trains crossing between north and south.
The money collected from the £10,000 fines will go towards funding deportations and further border enforcement.
Mr Kruger is expected to say: “Illegal and unvetted dangerous criminals, who cross into Northern Ireland are abusing the soft Irish border, using it as a backdoor route into the UK.
“The absence of checkpoints at the border does not remove the requirement to have a right to enter.
“Almost all illegal movement from the Republic into Northern Ireland is by scheduled coach or train, arriving at a handful of terminals.”
They would target terminals including Belfast, Newry, Banbridge and Sprucefield.
Mr Kruger is set to say: “We will impose a civil penalty of £10,000 per passenger on any bus or rail operator for each illegal immigrant transported into Northern Ireland.
“This is not a border check, it will be for operators to determine their own approach. The £10,000 fine will fund the deportation of the illegal migrants and further border enforcement.”
He will also call on the Irish government to share more data with the Home Office and introduce measures at Dublin Airport to stop anyone who is not an Irish or British citizen from boarding public transport heading north.
“The Common Travel Area and soft border is a hard-won compromise after decades of conflict.
“This pillar of the peace process is now being exploited by illegal migrants seeking to break into Britain,” he will say.
