Talks already under way to bring in electronic border with North
Revenue officials are working to develop a post-Brexit electronic customs system where vehicles will be able to cross the border between north and south without having to stop.
The Irish Independent understands that informal contacts have already taken place between Irish customs officials and their UK counterparts about the possibility of developing an integrated, joined-up electronic border system.
The head of Revenue's customs division said staff are at the early stages of a scoping exercise, and that the plan could take a number of years to fully build.
Anthony Buckley, deputy director general of Irish Customs with the Revenue Commissioners, said the aim is to develop a system whereby a truck can drive from one end of the island to the other without having to stop.
"Even if there's a free-trade agreement [between the UK and EU], we'll still need to know what is being traded, what's crossing the border," Mr Buckley told a Brexit briefing organised by the Irish Exporters' Association (IEA).
"Our design challenge, as I like to term it, is that a truck should be able to drive from Cork to Belfast or from Holyhead to Galway, without stopping. That would be the ideal, and we want to achieve that.
"We're starting the design process at the moment. We've already started the scoping and we will be building, but it will take us two or three years to build."
Revenue's aim is to ensure that information about a truck's load, for example, could be put into a computer on this side of the border, and then be automatically conveyed to the UK authorities in the north.
The movement of the truck could then be monitored in an M50 eflow-style electronic camera system.
Customs clearance facilities would have to be provided, Revenue believes, but they don't necessarily have to be at the border.
Revenue is looking at the possibility of using existing tax offices in the border areas.
But at the border itself, vehicle examination areas may need to be established. Spot checks of vehicles may have to take place to combat smuggling and fraud.
Currently, as a European Union member state, the UK is able to trade with the rest of the EU on a tariff-free basis.
Once Prime Minister Theresa May invokes Article 50 and begins the formal Brexit negotiations, the UK will then have at least two years to renegotiate Britain's trading relationship.
But what that would mean, and how it would look, in terms of customs procedures, remains to be seen.
It is of particular interest in Ireland's case, given the border with Northern Ireland, and the political desire to avoid a return to a physical border.
It is understood that up to 10 staff in Revenue are at the early stages of the scoping exercise.
Officials, as part of regular contacts, have spoken with colleagues in Sweden, Norway and Switzerland.
Earlier at the IEA Brexit event, Rory Montgomery, second secretary general at the Department of the Taoiseach, said that it was very likely that there would be a customs border between the Republic and Northern Ireland of some sort.
"Will there be a customs border? The answer is very probably yes there will be," he said.
"But to what extent will there be more significant trade restrictions and barriers, that will depend very much on the overall EU-UK relationship as it's worked out."
But he said there shouldn't be any reason to believe the free movement of people between Northern Ireland and the Republic, and the Republic and Britain, would be affected, as long as Ireland remains outside of the Schengen travel area.
"There is no pressure from our European partners to join the Schengen area," he said.
Mr Montgomery highlighted the fact that other EU leaders are aware of the issues facing Ireland post-Brexit.
"Chancellor [Angela] Merkel went to Ulaanbaatar in Mongolia for an EU/Asia summit.
"She talked to the Chinese and Japanese and others about Brexit, and she spontaneously mentioned Northern Ireland as an issue which was on her mind.
"Everybody knows that there are unique aspects to our situation."
Mr Montgomery, who has previously served as Ireland's ambassador to Paris, will be returning to the Department of Foreign Affairs & Trade as Ireland's "principal level negotiator at EU level" for the Brexit negotiations.
Taoiseach Enda Kenny has moved to allay fears of a return of a hard border between the Republic and Northern Ireland.
Speaking following a meeting with British Prime Minister Theresa May, Mr Kenny insisted that he would not allow a scenario involving the erection of "customs posts every mile along the road".