Can I change ownership of a single member llc in delaware to the spouse of the current member? How?

Hi, it depends on whether there is an LLC Agreement in existence. If the LLC Agreement states that the membership shares cannot be transferred, then a whole new LLC would have to be formed. If there is no LLC Agreement in existence, then a simple sale or transfer of the LLC membership interest(s) can be accomplished. I would recommend a written agreement to establish that the membership interest or interests have been transferred legally. I would also notify the Delaware Division of Revenue that ownership has been transferred. In addition, you should file an Amended Certificate of Formation with the Delaware Division of Corporations to show that the membership interest has been transferred. I would also highly recommend that the new owner have an LLC Agreement drafted for the company itself.