I registered a business name last year with the CRO. I didn't do any business or trade last year, do I have to file a return stating that everything is 0 or do I just leave it?
If you just registered the business name on CRO and never registered with revenue on TR1/TR2 for self-assessmnet sole trader or company and never actually traded then you can just file a cessation of use form for the business name on the CRO and that would be the end of it.