The law in this area is evolving and the strict application of the law of trusts would result in the funds in the bank account being held by your child in trust for your estate. If it is your intention to leave this child the funds in that bank account, you will need to provide written instructions to your lawyer and banker that this child is to receive the funds through joint ownership. In other words, you have to instruct that a trust is the intended result. There are easy ways to do this, and your banker may have a form to complete to document this. Our office can also prepare such a document as part of your estate plan. Before making this decision, you should give us a call as there are other factors to consider when you have more than one child, or if your spouse may need these funds beyond your death.