Silly question perhaps but if you declare extra income to HMRC they give you the option to have tax due paid spread out via your tax code if you're PAYE or to just pay it online which is what I did.
What is the downside, if any, of the first option please?
Brilliant thanks Eric I'm a very basic 1257L employee this is just tax on additional investment income so I wanted to keep it simple so paid it in one go.
That makes sense as to the reason to do so - thank you