The Post Office says there has been "an unusually high number" of applications for an Irish passport from people in Northern Ireland, following the UK's vote to leave the EU.
While the UK as a whole opted to back 'leave' in the referendum, Northern Ireland voted by a margin of 56 to 44 percent to remain in the EU.
The Irish Department of Foreign affairs has also reported a rise in inquiries over eligibility for Irish passports.
Earlier it was shown that Northern Ireland had seen a spike in online searches for information on Irish passports.
“From looking at Google Trends, we can see that in the UK there's been a significant spike (+100%) in the last 24 hours of people searching for the term,” Michael Wilson, digital data analyst with Glowmetrics in Belfast told UTV.
“And by the looks of it, it's been almost entirely generated by people within Northern Ireland."
Secretary of State Theresa Villiers has said a referendum on a united Ireland would not be “justified or helpful” at present.
Taoiseach Enda Kenny has said “the implications for NI and relations will require careful consideration” following the UK's Brexit vote.
Northern Ireland’s leaders have been divided in their reactions to the United Kingdom’s decision to leave the European Union.