The shutdown of schools and colleges and other coronavirus-related restrictions in the Republic are expected to hit the Northern Ireland economy.
Demand will drop for goods and services sourced from here as schools, colleges and public buildings in the South close down until March 29.
Large numbers of companies in Northern Ireland, including outsourcing firm Mount Charles, have focused on the Republic as a close-to-hand export market in recent years. According to cross-border trade body InterTradeIreland, cross-border trade reached an all-time high of £6.5bn in 2018.
There was £4.2bn sold from North to South, and £2.3bn from South to North.
Total cross-border trade in goods was worth £3.4bn, while services were worth £3bn. And at £715m, food, drink and tobacco was the category accounting for the biggest share of sales to the Republic.
Mount Charles has a four-year catering services contract with Maynooth University in Kildare for its 14,000 students, staff and visitors. It also has other deals with Griffith College Dublin, the Public Appointments Service, Ordinance Survey Ireland, Abbey Theatre, National Aquatic Centre and Custom House in Dublin. Many of those organisations will have now closed their doors, which will hit their suppliers' bottom line.
Aidan Gough, InterTradeIreland designated officer, said its offices are still open "at this point". He added: "Continuity plans are in place to ensure we continue to deliver our supports in a way which safeguards our staff and stakeholders. Covid-19 will have a disruptive impact on many of the businesses we support.
"We're encouraging firms to consider three initial steps - protect your employees and follow all the relevant guidance from health authorities; test for stress by making a contingency plan and ensuring liquidity; and maintain an open dialogue with staff, customers and suppliers."
He added: "The health and wellbeing of our staff is our number one priority.
"We have provided guidance and advice on sanitisation, remote working and continuity planning.
"In all circumstances we will be guided by the advice from the relevant public health authorities."
Meanwhile, the Broad Economy Sales and Exports Statistics from the Northern Ireland Statistics and Research Agency said exports from NI were estimated to be worth £11.2bn in 2018. Exports to the Republic were worth £4.17bn.
Across all export markets, sales of goods were £8.7bn in 2018, an increase of 5.8%. Services exports were worth £2.5bn.
In a special Facebook live broadcast for the Belfast Telegraph, virus experts Dr Lindsay Broadbent and Dr Connor Bamford answered readers' coronavirus questions.