Does firming an unconditional offer place any obligations on me?

My question goes as stated in the title: I'm planning on firming an unconditional offer I received, but which I'm not yet sure if I want to pick up in the end (and go to a university outside UK). If I accept the offer on UCAS (and complete all the other admissions paper work) is there any obligation for me to attend the university?

This question particularly concerns tuition fees: how far until the admissions process can I go before I am forced to pay the tuition fees (UCAS deadline? Matriculation?)? The university in question is the University of Cambridge, if it makes any difference.

Any help or tips towards useful sources is appreciated!

Firming an offer just locks you into a contract to not apply elsewhere *in the UK* in this application cycle without the agreement of your firm choice.

You generally aren't financially committed until enrolment (for fees) or signing of contracts/deposits (for accommodation.

If you're an international student requiring a tier 4 visa then you'll also be committed as soon as you use your CAS to get a visa and won't be able to swap for another uk university without a bunch of hassle (and expense).