It is not necessary to have a Registered Business Name Number or Companies Registration Office Number to register a .ie domain.

If you are registering a .ie domain for Business use, the IEDR will look for proof that you are a Sole Trader i.e a VAT Number, copy of a letter from Revenue confirming you are registered for Income Tax.

If you are looking to secure a .ie domain for FUTURE Business use, you can apply as a Discretionary Applicant.  The IEDR will just look for a copy of an Irish Drivers Licence and a brief explanation as to what the domain name means and what it will be used for in this case.