Statutory auditors that express an audit opinion on an entity incorporated outside the EU but which is quoted on the Irish stock exchange are (with certain exceptions) required to register separately with IAASA in accordance with Regulation 113(1) of SI 220 2010. FAQ3 on IAASA's website gives more details about the exceptions to registration.
There is a series of application forms for those statutory auditors that are required to register.
If, however, those statutory auditors are already registered with ICAEW as Irish statutory auditors, then a streamlined approach is applied and the auditor need only to write to IAASA detailing
The statutory auditor must be registered before the audit report is signed. Further detailed guidance, including copies of the relevant application forms, is given on IAASA’s website.