North-south trade topped €5.4bn in the first nine months, CSO figures show, in an apparent boost for all-Ireland economy since Britain left the EU and Northern Ireland remained in the single market.
The latest official trade figures show that exports of goods from the Republic to the North surged by €835m to almost €2.6bn between January to the end of September compared with the same period a year earlier, while imports from the North to the Republic climbed by over €1bn to €2.8bn.
The figures continue the trend which has been much remarked on by hauliers and by business-owners that cross-border trade has developed at a remarkably fast pace since the UK exited the EU from January 1.
Under the deal, the North remains in the EU's single market, which means there are no checks on goods travelling up and down the island of Ireland, but the EU and UK had agreed on checks on some goods entering the North and Republic from British ports.
"The September CSO figures for the import and export of goods have confirmed that there has been a significant increase in cross-border trade on the island of Ireland in 2021 following Brexit," said Grant Thornton Ireland partner Jarlath O'Keefe.
The figures suggest that exports from the Republic, particularly driven by pharma products, across the Irish Sea to Britain, have grown, possibly because Britain has so far deferred implementing a range of checks it signed with the EU last Christmas under the Trade and Cooperation Agreement (TCA).
Britain has since threatened not to implement the nine-month-old TCA by triggering a disputes mechanism, because the London government says it is unhappy with the way full checks will operate on goods between Scottish, English, and Welsh ports and Northern Ireland.
The CSO figures show that exports to Britain from the Republic rose by almost €2bn to €10.6bn in the first nine months from a year earlier. Imports from Britain plummeted by €2.4bn to €9.4bn over the same period.
In September, the EU accounted for 40% of goods exports from the Republic, the US accounted for around 30%, and the UK made up a 10% share.
Mr O'Keefe said that trade with Britain remains important, but "the over-reliance" on trade across the Irish Sea was "no longer the case".