Joint accounts, life insurance and retirement accounts usually do not have to go through the probate process, but do not act as a complete will substitute. Many spouses own real estate, bank accounts, stocks and bonds and other types of property as husband and wife with the right of survivorship. This means that if you die, leaving your spouse behind, your jointly owned property passes automatically to your surviving spouse, regardless of what your will says.
Life insurance and retirement accounts are contractual documents. You have to tell the companies with whom you contract who you want to receive your death benefit. Your beneficiary designation will determine who receives the benefit regardless of what your will says. Beneficiary designations and joint accounts are good estate planning techniques to avoid probate, but should only be considered as part of a complete plan that includes a will. Your will directs who you want to be your personal representative, what type of service you would like to have, how you want your personal property distributed and how your debts and taxes are to be paid.
Joint accounts and beneficiary designations cannot answer those questions that your loved ones will have at the time of your death.