What are circumstances under which spouses bad credit will impact the other spouse's credit rating?

The only way this can happen is when they have joint accounts and then depending on how the accounts are paid the credit of both people will be affected.

What are circumstances under which spouses bad credit will impact the other spouse's credit rating?
It won't impact your rating, as each individual has his/her own file at the bureaus. It will impact your life, however, if you want to co-borrow to buy a house or car, because the lender will pull both reports.
Reply:When you have joint accounts
Reply:only if the spouse with bad credit defaults on a joint account