Is it legal to distribute funds from a joint checking account after death?
Double check with the bank to be sure you are a joint owner on the account. If you are listed as a joint owner of the checking account--and it sounds as if you are--then you can certainly write checks for your neighbor. You could also write checks to cover your own needs, so your neighbor showed a lot of trust in adding you to his account.
When your neighbor dies, you will become the legal owner of the money left in the account and can do whatever you choose to do with it. If you donate the money to the nonprofits as directed, you should know that the gifts will legally be considered to come from you, not from your neighbor after his death.
A durable power of attorney for finances, in which your neighbor would name you to act as his financial agent, would also give you the power to write checks for him. But in that arrangement, you wouldn't be the owner of the account during his life or after his death. Most people use this approach when planning for their incapacity because they don't necessarily want to give another person their money; they just want to provide for someone to manage it for them.
