<prompt> Human: Throwaway account, but Im a regular reader. Over Thanksgiving weekend, my mother-in-law mentioned to me that my husband was taking her to our credit union the next day to make her an authorized user on all of his bank accounts including the joint bank accounts he shares with me. He had not mentioned this to me before, so I held my tongue and smiled politely at her until I could talk to my husband alone and ask him not to do this. Even though I confronted him about it that night, he still added his mother as an authorized user to our joint bank accounts despite my request that he not do so.I know this probably sounds like a question for rrelationship_advice, but I really need some information on the potential financial impact this could have on our joint bank accounts. Yes, I felt completely flabbergasted that he could think of making a major financial decision without consulting me, but I can handle the emotional part on my own. Im really here for financial advice. Background information: Weve been married a little over a year, and we have both separate and joint bank accounts. I have no other reason not to trust him with money. He has been very responsible with money until now. My husbands reasoning was that if something catastrophic happens to both of us, like we get in a car crash and die, he would want his mother to be able to access his money and our money without having to jump through a bunch of hoops. Shes 75 and lives in another state. I dont believe his mother would do anything to take his money or our money, or inflict ill will on us. She has plenty of money of her own. In fact, I doubt shed even look at our bank statements unless something happened to us. She is a widow, and when her husband died a few years ago, she added my husband her son to all of her bank accounts so he would be able to handle her affairs if something happened to her. My husband feels like he was just reciprocating this by adding her to all of his and our accounts. When my husband went to the credit union to add her to hisour accounts, he was told that I would have to sign some paperwork in order for his mother to be added to our joint accounts. However, I was not present at the CU, so they brought the paperwork home for me. I refused to sign. When I called the credit union the following day, however, the representative told me that his mother, in fact, had been added to our joint savings and checking accounts, because it only required the signature of one primary account holder and my husband, as a primary account holder, signed the paperwork. I have many problems with him adding his mother to our account for a variety of reasons. First and foremost, I feel I should have been consulted about this because we are married and we should make financial decisions together, not unilaterally. My husband can see my point here, but he fails to see how this could be dangerous to us financially. My question for rpersonalfinance is what are the potential financial impacts this could have on us, and on me? Shouldnt my husband and I make a will, instead of just adding people to our bank accounts, in case we both die? Also, if something horrible happened and my husband died and I survived I get sad just thinking about it, would I have to fight his mother for control of our joint bank accounts? Its my money in there too. I know people do crazy things when people die. What other, if any, potential financial problems could this situation create? Or if I am I totally overreacting here, please feel free to call me out on it. TL;DR: My husband added his mother as an authorized user to our joint credit union accounts without my consent. Aside from the obvious emotional violation of trust, I am having a hard time explaining to him why this is a bad idea from a financial standpoint. Its not that I dont trust his mother; its that I feel this will make things extremely complicated should one or both of us die. What rights do authorized account users have that could be problematic for us in the future? Please help me understand what this all means from a financial aspect even if my instincts are wrong. ---UPDATE: I am overwhelmed by the number of responses. Thank you to those who took the time to post constructive, helpful comments. I showed my husband this post, and it was ueatsbabydingos comment about his mother getting in a car accident with Oprah that really struck him. He called our credit union to verify that we could, in fact, be financially implicated if his mom was sued and vice versa. When the CU said yes, he said he would be removing his mom from all of his and our accounts. We are going to speak to the credit union about them adding my MIL to our accounts without my signature, and we are probably going to switch to a different CU.  <response>: Until you get this all sorted out, I would consider figuring out how much of the money in those accounts is yours, withdraw it and put it in your personal accounts, then make sure your paycheck is not automatically deposited into any of these. 1 Gives you peace of mind until this can be sorted out 2 if you cant kick her off the accounts, you wont have to worry about how it affects your side of the money at least though your husbands would still be a concern 3 maybe then youre husband would realize how important it is to you and just remove her himself. 