It passes automatically to the other without a will and without probate. This is a strong case only for committed couples, gay couples, for example, whose families disapprove of the relationship and might challenge a will. A carefully drawn will usually can’t be broken, however, except by a surviving spouse who was not left the share of the property required by state law.
It is a sign of a good faith.
It is convenient. A mother and daughter living together may want a joint account for household bills.
The strong case against
If you want to take your property out of joint names and the other person refuses, you may have the devil’s own time getting it back. Only bank accounts are simple to reclaim. You just take the money out (unless the other person got there first). Either owner can empty a joint bank account. You would have to sue to get your money back.
You might need both signatures to sell an investment or to cash a check for the proceeds of a sale. What if your ex-mate gets sore or leaves town?
Say you put your investments in joint names with your son, who manages them for you. His business goes broke. His half of your property could be attached to pay his debts. (He can manage your money just as well with a power of attorney or through a trust.)
The relationship might end but not joint ownership. For example, say that you and a boyfriend own a house together. Even if the boyfriend buys you out, you are still on the mortgage and are fully responsible for the debt. Only the lender can release you and the lender may refuse to do so. If your boyfriend (ex-boyfriend) quits paying the mortgage without your knowledge, the default will show up on your credit report. Ditto any liens that your ex’s creditors put on the house. If the bank comes after you for the mortgage payments, you will be supporting your ex-boyfriend’s real estate investment and getting nothing in return (unless a written agreement allows you to force the sale of the house to recover the money you put up).
All joint property is taxed in the estate of the first owner to die, except for anything that the survivor can prove he or she paid for. These rules, incidentally, apply only to joint owners who are not married.