Shoppers from the Republic spent about €435 million in Northern Ireland in the year up to July, according to a new report from the Central Statistics Office (CSO).
The CSO says this figures is probably an under-estimate because it doesn’t take account of seasonality, in particular the pre-Christmas rush.
Some 16 per cent of households made at least one shopping trip to the North during the period, and shoppers from Dublin accounted for one-third of all trips.
The nearer shoppers lived to the Border the more often they shopped in the North, the survey found, but the amount spent varied in inverse proportion to distance from the Border.
Overall, those most likely to have shopped in Northern Ireland were those living in the Border area, two-income households, those aged between 30 and 44 and households with children.
Some 41 per cent of households in the Border counties shopped in Northern Ireland, but this figure fell to 21 per cent for Dubliners and just 9 per cent for shoppers from the south-east, mid-west and south-west combined.
The average amount spent on their most recent trip was €286, of which €114 went on groceries and €32 on alcohol. Households in the mid-west, south-east and south-west regions combined spent an average of €492 on shopping on their most recent trip, compared to just €150 for Border households.
Eighty per cent of consumers said they bought groceries on their shopping trip up North and alcohol was the next most popular purchase, at 44 per cent. Clothing and cosmetics were bought by 42 per cent and 26 per cent of households, respectively.
The average household in the Border area made six cross-Border shopping trips a year, while of those who made the journey, the average was 14 trips in a year.
This is the first time the CSO has included questions about cross-Border shopping in the quarterly National Household Survey.
Retail Ireland has claimed cross-Border shopping cost the state 11000 jobs and €220 million in 2009. The group estimated that one job was lost for "every 150 cross-border shopping trips" made.
The group attributed much of the shopping trips to the North to cheaper alcohol, saying half of all alcoholic purchases made in Ireland this year, were in the North, which has about a third of the island's population.
"Excise levels on alcohol should be reduced by 20%, as alcohol is a huge factor in cross-border shopping trips...we have the highest excise in Europe for wine and the second highest for beer and spirits," it said.
