This question already has an answer here:
A few years ago I travelled to the Republic of Ireland from the UK, taking a ferry to Belfast and driving across the border from NI. As a UK national this wasn't a problem, but I'm trying to work out how it would work if I weren't.
For this scenario, let's assume:
- I have a valid UK long-term visa
- I'm not eligible for the Irish visa waiver scheme for holders of UK visas
As stated in this question I would need to get an Irish visa, but once I had it would it be legal to just cross the border, or would I need to report somewhere to have it checked / get my passport stamped?