All Nestlé products sold in Ireland are imported from Britain, meaning any changes to trading rules and regulations post Brexit would push up the company's costs, its UK and Ireland chairwoman has warned.
Fiona Kendrick also signalled that Border delays would hit its exports to here more than to other EU states, as the company has no distribution centres in Ireland.
Ms Kendrick said Nestlé brings 22,000 tonnes of products into Ireland every year, via 2,500 truck movements, directly to its customers.
About 82pc of that is manufactured in the UK, with the remainder coming from Europe through Britain. The Republic of Ireland market accounts for 6pc of Nestlé's business.
"What is very important for us is regulatory standards. Absolutely key is that we have a convergence of that, that we avoid red tape," Ms Kendrick told the House of Lords EU Committee.
"If I take Ireland as an example, every product that we manufacture for Ireland is identical [to those sold in the UK], from the front of pack to the actual nutritional labelling on that. If indeed we have different regulations, that will require different packaging, that will require therefore a very different requirement in our factories, which ultimately drives a lot of cost. We try and eliminate all costs."
Ms Kendrick said Nestlé employs 700 people in Ireland with a factory in Limerick that produces infant formula.
"For us, finding a solution is very, very important," she said.
She said the company exports directly to Belfast for its Northern Ireland customers, and to Dublin for those customers in the Republic. There are no distribution centres here, Ms Kendrick added. She said the company does not transport its products across the Border, although its customers may do.
"In the EU [in continental Europe] we do have distribution centres there," she said. "So if there were a delay moving it across, it's a big direct impact on our customers in Ireland."
Leigh Pomlett, executive director of freight management group Ceva, and president of the Freight Transport Association, told the committee that to manage Border checks on the island of Ireland would be huge and complex.
"The interesting thing about that Border is that there are so many crossing points. It is like a colander of sorts," he said.
James Hookham, deputy chief executive of the Freight Transport Association, said the levels of trade between Ireland and Britain have grown to the point where border checks at ports could not be accommodated at UK ports.
"Areas such as Holyhead and the south Wales ports, but even in the port of Liverpool, there simply isn't the physical space for customs and border controls to be conducted."