How old do I have to be to open a money account or be a joint account holder? September 10, 2020 23:01 Thanks for your interest in SoFi Money! You must be 18 years or older to open any SoFi Money account with us whether joint or individual. For more information on SoFi Money Eligibility go here. Related articles Who can open a SoFi Money cash management account? Does SoFi offer Custodial account options? How do I add funds to my Automated Invest account? I have a joint Money account. How does cash back work? How do I upload a document to my SoFi Money account?