Applying to uni whilst at another one

Basically, I have started my application for the 2026 academic year and I am still in another university for financial reasons. I emailed my old sixth form for a reference and they said yes but also offered their buzzword. Would using it for my application whilst being at a university affect the UCAS application at all or is it okay to use it?

Its perfectly okay to apply though your old school - but most Unis will still expect a reference and grade transcript from your current Uni.