The bank said it would continue to use its existing licensed EU-based bank subsidiary in Dublin to serve EU clients after exit day.
"Our preparations are well advanced and we expect to be fully operational by 29 March," the bank said in a statement.
A total of 5,000 clients are involved in the Brexit-related switch, ahead of Britain’s proposed exit day on 29 March.
According to the Financial Times, the move by Barclays has been planned since 2017. Yesterday’s decision means “the bank can transfer ownership of its branches in European cities such as Frankfurt, Paris and Milan from the UK to Barclays Bank Ireland”.
Scale of transfer is 'huge'
In his judgment, Mr Justice Snowden said: “On any view, the scale of the transfer of business . . . under the scheme is huge.
“The design of the scheme has been based upon an assumption that there will be no favourable outcome of the current political negotiations between the UK and the EU as regards passporting.”
Last week, British Irish Chamber of Commerce president John Cronin told Gazette.ie that the range and sophistication of fund-asset work was broadening in Dublin as a result of Brexit.
In the event of a no-deal hard Brexit, UK-based banks will lose passporting rights to function in the EU's single market.
The High Court’s Mr Justice Snowden said in his judgment: "Due to the continuing uncertainty over whether there might be a 'no-deal' Brexit, the Barclays Group has determined that it cannot wait any longer to implement the scheme.
"In light of the large volume of business to be transferred, the scheme contains a number of phased dates upon which the transfer of the different types of business, and the business of the branches in Spain, Italy and France, will become effective.
"The overriding requirement, however, is that BBI [Barclays] must be legally and operationally ready to conduct all relevant regulated business with the in-scope clients by no later than 29 March 2019, which is the date currently set for Brexit."
Other banks, such as the Royal Bank of Scotland, Lloyds, Goldman Sachs and Morgan Stanley, have also set up continental hubs as part of their Brexit preparations.
There are job and tax consequences for Her Majesty’s Revenue and Customs as hundreds of billions in assets are shifted out of London, though these have yet to be determined.