EU citizen cannot trade in T212 if was born in the US?
Welcome to the Community, @gejibe 
For the time being, we don’t provide our services in the US. Due to this, we also can’t offer our services to US-born people or people with dual US citizenship.
This makes no sense to me, I went to the bank to sign papers for being part of a bank account for a minor and the bank requested me to sign the W-8BEN.
I mention “• You are a U.S. citizen or other U.S. person, including a resident alien individual . . . . . . . . . . . . . . . . . . . W-9” and regardless of that, the bank told me I had to fill the W8, because the W9 is for US taxpayers, and I was not.
So makes no sense, something is being miss between the lines, and I’m sorry to say, but I believe it’s here rather than my bank, my bank knows me and has all the info on me, here all you have is the information I provided and that’s limited to “I was born in the US, but live my whole life in EU”
T212 is not equipped to deal with your fairly unique circumstances, the US taxes based on citizenship and not residency and 212 evidently doesn’t have the controls to collect that on your behalf.
It’s not impossible for you to get a brokerage account, it is, at least for now, impossible here.
This messes me up badly because I don’t even hold a US passport anymore. I was just trying to be as transparent as possible.
I think that’s perhaps a little dramatic. There’s plenty of options out there.
Really? What EU brokers would accept me?
I have been through this all myself when I used to be a US citizen. If you are born in the US then you are automatically a US citizen and taxpayer, even if you have never had a US passport or US source income.
Such “US persons” should not use the W8-BEN form. It says so on the form. If your bank told you to use W8-BEN, they are mistaken, unfortunately. Does you bank know you were born in the US and once had a US passport?
The options for investment accounts for US persons living outside the US are severely limited. Most non-US investment platforms are exactly like Trading 212 in refusing to accept US person clients. One reason is the very onerous reporting requirements associated with with the FATCA rules.
Many people caught in this situation decide the best course of action is to “retire” their US citizenship. There is a Facebook Group called “Renounce US Citizenship, Why and How” that is worth looking at.
The other option is to work with a broker that accepts US person clients. I think that in Europe this incudes Interactive Brokers and Charles Schwab. As a US person you will not incur 15% withholding tax on US dividends, but will be expected to pay your dividend tax when submitting your US tax return, with W-9.
Strictly speaking, everyone who is a US person is subject to US taxation and must file a US tax return annually if total income exceeds a certain threshold. However, if you have not yet entered the US tax system, you can “live under the radar”. The IRS will not come looking for you. The only nuisance is that banks and brokers will ask you for your place of birth or other tax residencies and will likely reject you as a client when they realise you are a US person subject to US taxation.
Your situation is very common, but usually a shock to a person when they first appreciate it. However, don’t panic. There are options.