Could it just be sub-account or category inside your actual account (legal entity) ?
Kinda like Microsoft creating a folder in C:\Users\You\My Documents, or Chrome creating C:\Chrome\Downloads without your explicit permission. Creating a fraudulent folder in YOUR NAME without your express permission is fraud! They even encourage you to "put your documents in there". Maybe that folder is a legal entity? Maybe try harassing customer service so they'll delete it for you?
It could be any number of things. Me engaging in a guessing game with you as to what it might actually be would be pointless. The fact that Betterment hasn't informed you or the OP of what it
actually is, as a financial institution, would concern me greatly if I were doing business with them.
When Wells Fargo started acting like a mosquito, treating me like a food supply, I walked, and fast. That was over 10 years before their games publicly blew up in their face. Their customer service was very polite and friendly too; useless, but friendly and polite. I was on a first-name basis with just about all of them before I got fed up and left.
But the story doesn't end there. Years later I was my late uncle's executor for his estate. All of his assets and accounts were with Wells Fargo. I got the court order I needed to prove my role as executor, and I liquidated, transferred, paid off, and then closed all of my uncle's existing accounts (a complete list of which was provided to me by Wells Fargo).
In order to take over someone else's accounts, you need more than just a court order. You need to present an official death certificate (not a copy) that Wells Fargo keeps for their records. So Wells Fargo had all the certifications they needed to know that my uncle--their now ex-customer--is dead.
Acting as executor, at the post office I changed my uncle's mailing address to my own. About 14 months later I got a statement for an account my uncle never had,
but mailed to my actual address, not to my uncle's old address, and in my uncle's name, with a balance due for an annual fee.
And this was 6 months after the congressional hearings. In California (where I live), an executor is personally responsible for settling all debts (including all taxes due in or before the terminal year) of the deceased, which can be covered by the deceased person's estate,
before paying the beneficiaries of the estate.Wells Fargo offers probate services, so someone there knows the California law. I had already paid out the estate to all the beneficiaries. Someone at Wells Fargo merged an executor's personal information with a deceased person's information, and created a new fee-bearing account with it. So here is Wells Fargo trying to rip me off again, even after I fired them so many years ago, and even after they got caught.
The fake account was eventually closed by Wells Fargo, several months later, with a somewhat obtuse apology for
"inconveniencing" me (actually addressed to my late uncle, though, not to me). I figure that was probably right around the time they decided to pretend to clean up their act.
The
"benefit of the doubt" has to be earned. Giving it away on a lark or a hunch is just asking for trouble.