Tax advice for short term

Hello,

Hoping someone can steer me in the right direction... question and detail below, thanks in advance!

I'm starting my own business as of the end of March, however my current employer hasn't managed to replace me as yet so I've agreed to work for the 3 days a week for a few months until they find a replacement. The thinking being that it gives me some financial security but also is a favour to them.

My work want to just change my contract from 5 working days to 3 but I'm guessing that would mean lots of complications as I'd be billing other work as an LTD and receiving PAYE for the 3 days too (at the higher tax rate). I think a cleaner approach would be to freelance for them and have everything in one place, rather than getting paid PAYE. Is that about right?

Any advice greatly received...

Thanks!