If I did bad on a Subject Test, do I still have to submit it to UCs?

So I took 2 subject tests today and I was wondering if I should cancel my scores cause I feel I did absolutely horrible on one of them. On one of them I did fine, but terrible on the other and I still want to submit the score I am confident about. Is it more worth to cancel my scores so they don’t see my horrible score, or do I even have to submit that subject test score to UCs. I know UCs look at best scores so everyone always says to send all scores, but I cannot retake this test. I also know subject tests aren’t required so I’m wondering if it is necessary at all to still submit the scores.

I don’t really see why you wouldn’t send them in. They’re subject tests, so if the school doesn’t require them, send them in anyways. It doesn’t matter if you did good or bad on them. They won’t hold them against you because they don’t require them with the application. I would send them in anyways, because if you end up doing good on them, they will definitely add those tests to improve your application. If you did bad, then they won’t care. Just send them in.

You do not have to send SAT subject test scores to the UCs if you do not want to. They are optional.

Thank you

And as some have confirmed by asking the UC’s, the UC rule that requires you to provide all SAT scores that you have does not apply to subject test scores and you can send whatever subject tests you want to send.