Legal Question in Wills and Trusts in Washington

Assuming you mean a joint tenancy account with right of survivorship, the surviving account signatory(ies). If it is a tenancy in common, the decedent's half (or portion) is part of the estate. The bank can tell the survivor(s) what kind of account it is.

If an account is owned jointly in the names of two or more people and it's designated "with rights of survivorship," then when one account owner dies the surviving owners will simply continue to own the account. Probate of this type of joint account simply won't be necessary. Instead, all that the surviving owners will need to do is show the bank or investment company a death certificate for the deceased owner and then the deceased owner's name can be removed from the account.