Can I open a current account in Ireland before arrival, maybe online? I am currently in US, can I use US address while opening account?
You need to be able to prove residency in Ireland before you can open a bank account here. My partner had a lot of difficulty getting an account when we first moved here. I was able to get an account of my own easily with proof of address and relevant identification some years later. If you're not an Irish citizen, you may struggle initially. But once you have paperwork with your address on it, such as a tenancy agreement, you should be set. Some banks are more accommodating and helpful than others when starting out though. It's also worth noting that any current account will charge you, regardless of being an Irish citizen or not.