A total of 366 charities have so far missed their registration deadline, according to the Charity Commission for Northern Ireland – 10 per cent of the organisations so far contacted.
Under the Charities Act (Northern Ireland) 2008, trustees have a statutory duty to register their charity and have three months to submit their application from the date they are contacted.
The commission started asking charities to register in tranches in December and has so far contacted 3,676 organisations.
In a statement issued on Friday, the CCNI said that 366 charities had failed to register within the three-month period.
Frances McCandless, chief executive of the commission, said: "We would prefer to have organisations apply to register with us when called forward – if they do not, the trustees of those organisations could find themselves facing High Court action."
The charities being called to register are based on the deemed list of organisations that have registered with HM Revenue & Customs for tax-free status, which includes 6,186 charities. The commission is asking charities that are not on its online registration list to complete an online expression of intent form before the end of December.
The commission said that it would issue a warning letter to organisations that failed to apply, publish their details on its website as being non-compliant with the legislation and inform HMRC where applicable.
The regulator expects that it will take between three and four years to register the estimated more than 7,000 charities in Northern Ireland.