Domestic flights within the UK (e.g. London / Edinburgh) require positive ID checks, since around 1995 or so. So nothing changes regarding flights from NI to G

Domestic flights within the UK (e.g. London / Edinburgh) require positive ID checks, since around 1995 or so. So nothing changes regarding flights from NI to GB. There are usually few checks on the ferries, but one is advised to carry proof of citizenship, as one can be asked to prove that one is entitled to use the CTA. Separately, it was recently announced that third country nationals traveling from Ireland to NI would not require prior authorisations. i.e. the UK will not police travel across the intra-Ireland brder.