Some British businesses are asking customers in the Republic and Northern Ireland to pay additional charges amid post-Brexit costs.
The Irish Times reports that suppliers in Britain are asking companies in the North to cover costs such as shipping and red tape, as a condition of getting their orders filled.
Some British suppliers have told companies that they will stop selling them goods, as new complications and customs checks surround post-Brexit trade.
One British-based company is seeking £140 (€157.13) to cover paperwork needed to ship from Britain to the Republic – £70 each for exit and entry documents at either side of the journey across the Irish Sea.
A letter from the company, which regularly deals with builders’ suppliers north of the Border, also shows it is seeking £70 (€78.37) from its customers in the North – £35 each for exit and entry documents.
According to the firm, its shipping companies have said that the best deal for Irish customers may be to arrange shipping themselves and collect any goods they order from the British company’s premises.
Some members of the Federation of Small Business in Northern Ireland had been affected by the problem, Roger Pollen of the Federation confirmed.
However, he said it was difficult to say how widespread the issue was at this stage.
Mr Pollen said that the new trade regime had only just been introduced, while Covid-19 restrictions were also hampering normal business activity.
There are also periods of grace for different categories of goods, set to lapse between the end of March and the end of June, that might be obscuring other difficulties.
The problem appears to mainly affect small businesses, with the Confederation of British Industry in Belfast, which represents many larger employers, saying it had received no reports of extra charges from its members.
It comes as other post-Brexit trading difficulties have seen Britain's major supermarkets warn the UK government that "urgent intervention" is required to prevent significant disruption to Northern Ireland food supplies in coming months.
Britain is no longer part of the European Union's single market and customs union, but the British-run region of Northern Ireland has a foot in both camps under a post-Brexit trade deal — it is part of the UK's customs territory, but also still aligned with the EU's single market for goods.