what happens if I accept an offer but do not go to that uni

My situation is:
In ucas all my desicions is received, and I have accepted two offers as firm and insurance.
But I have also received an offer from another uni(not in ucas) and I want to go to that uni
So can I do not go to any uni after accepting the offers?

Are your UCAS firm and insurance choices both conditional offers? (Clearly your firm choice is, otherwise there would be no need for an insurance choice.) So it could be that when your exam results come through, you don't meet the grade requirements for either and so have no confirmed place anyway. At which point, you'd be free to attend the non-UCAS university.

If you do meet the conditional offer of your UCAS firm choice (or failing that, your UCAS insurance choice), then you can simply click "Decline my place" in UCAS Hub.



It would be unwise to do anything before your results come through, as you may not meet the conditional offer you have received outside of UCAS - meaning that you might want to take-up the UCAS firm or insurance place anyway.

(Is your non-UCAS option a non-UK university by the way? I ask as applications for all full-time undergraduate degrees in the UK must go through UCAS.)

You are not tied to any offer until you have actually formally enrolled at that Uni - usually online and from late August onwards. You can withdraw up to that point with no penalties - just be mindful of signing any accommodation contract that will usually come with cancellation fees.