General   (General discussion, talk about anything.)

Mollie, you are perfectly correct. But, get ready for the keyboard warriors.
Please read what I typed and then read the follow-up remarks.
What is sometimes unbelievable, is what some people post. On this particular page, one member tells us what you should or should not do and what you don't need etc, but tells us that he has never been to Ireland.
I was there in the last quarter of 2019 and where I spent my time, I only used euros.
I would say that Northern Ireland does not have the euro and it possibly isn't accepted in many places.
As you pointed out, only Northern Ireland is part of the UK. Southern Ireland is not part of the UK and it is in the EU.
Therefore, I would not be so sure that British tourists can cross borders with great ease, speed and without a passport.
My philosophy has always been, it is better to be safe than sorry.