Hey Ryan, best info for us on island would be IOM FATCA and CRS details
To my mind; CRS would be the main thing that effects us (FACTA is more about US Citizens finding a line of reporting back to the IRS in the states; not applicable for me personally but if it is for you then details will be in that link)
CRS would help identify if a UK person was claiming to live/work in the island and holding off-shore money and not paying tax on it (income or tax on interest for example).
So if you’re a Manx resident, paying Manx tax, there shouldn’t be any implications (and there haven’t been for me for 5 years holding a lloyds group bank account while being an IOM resident). HMRC would simply be told you’re generating interest/have a balance in IOM and you’re a resident there and any tax due would be due to the IOM Treasury.
FACTA/CRS isn’t any sort of assessment submission to HMRC. I’ve got a number of UK bank accounts. The only query that got raised was where interest on tax should go/be calculated; and it was IOM for me. Didn’t hear anything of it after that.