All Carphone Warehouse stores in Ireland are closing with immediate effect.
The closure of 81 stores is set to lead to over 400 redundancies, while the firm's web operation is also closing.
Some staff will be kept on by the company over the next couple of days for "operational support".
In a statement, the firm said: "As part of Dixons Carphone’s broader transformation, of one joined up and profitable business, it has made the difficult but necessary decision to close Carphone Warehouse in Ireland, in line with its decision to close all standalone Carphone Warehouse stores in the UK in 2020.
"Customers are changing the way they buy mobile devices and connectivity, replacing their handsets less often and buying them separately or as part of more flexible bundles.
"Although these changes in behaviour were anticipated, they were expected to occur over a longer period of time. However, the change in shopping behaviours has been accelerated by the pandemic."
They say they've closed immediately as footfall is 'down significantly' as a result of the ongoing restrictions, and they don't expect many new customers to sign new contracts.
They're assuring customers their network coverage will continue as normal, and anyone with issues should contact their network directly.
The firm's parent company says they'll also continue selling phones and accessories through Currys PC World.
Carphone Warehouse closed dozens of stores in the UK in 2018, although its Irish stores weren't impacted during that round of closures as business was "performing in line with expectations".
