If you have a living trust, and you and your spouse are co-trustees, either can act and have instant control if one of you becomes incapacitated or passes away. If something happens to both of you, or if you are the only trustee, the successor trustee you personally selected will step in. If a corporate trustee is already your trustee or co-trustee, they will continue to manage your trust for you.
If you become incapacitated, your successor trustee looks after your care and manages your financial affairs for as long as needed, using your assets to pay your expenses. If you recover, you resume control. When you die, your successor trustee pays your debts, files your tax returns and distributes your assets. All can be done quickly and privately, according to instructions in your trust, without court interference.
Successor trustees can be individuals (adult children, other relatives, or trusted friends) and/or a corporate trustee. If you choose an individual, you should also name some additional successors in case your first choice is unable to act.