Bankruptcy and non registered co-signor
I am currently considering the bankruptcy route due to personal circumstances. A few years ago someone co-signed a loan for me – they signed the paper work but apparently they weren’t registered on the loan as co-signor. What happens in this case. I know normally they become responsible for any payments I am unable to make, etc…but what if they haven’t been registered as co-signor?

I am not sure what you mean by “they weren’t registered on the loan as co-signer”. If they signed the loan documents then they are likely responsible for the debt.
Two options: (1) wait and see what happens if/when you file bankruptcy. Call this the “let sleeping dogs lie” approach; or
(2) contact a lawyer and/or the lender to discuss the legal ramifincations of this failure to register.
Sorry I can’t provide you with a better answer.