Situation · A letter arrived
Your bank asked for a U.S. tax number. What should you do next?
The letter is a routine identification request, not a tax bill and not an accusation. It does contain three separate problems, though, and mixing them up is what makes this stressful.
By Danilson Ramos · Founder, Atamatax
Updated September 2026
Takes ~2 minutes — then continues into starting your full return.
A letter or a secure message arrived from your bank. It asks whether you are a U.S. person, it may mention FATCA, and it probably asks for a TIN — a U.S. taxpayer identification number — or encloses a form called W-9. If you have lived your whole life outside the United States, this reads like the opening of something serious.
It usually is not. What follows is what the letter actually is, and then the three separate things it is asking you to sort out — because the single most useful thing you can do right now is stop treating them as one problem.
Why your bank is asking
Under FATCA, financial institutions outside the United States identify which of their account holders are U.S. persons and report those accounts. To do that they have to ask, and they have to ask everyone rather than guess. Something in your file — a U.S. birthplace, a U.S. address that was once on the account, a phone number, a standing transfer — flagged you as someone to ask.
What the letter is not
- It is not a tax bill. Your bank has no idea what your income is in U.S. terms, has not applied any threshold, and has not calculated anything.
- It is not an IRS letter. It came from your bank, under an obligation your bank has. The IRS did not write to you.
- It is not a determination that you are American. It is a question. Banks apply indicators broadly and get it wrong in both directions.
- It is not an accusation. Nothing about receiving one of these suggests you did anything wrong.
The three problems in one envelope
This is the part worth slowing down for. People answer these in the wrong order — or answer one and assume the others are handled — and that is where the cost comes from.
| The question | Who answers it | What it turns on |
|---|---|---|
| What does my bank need from me? | You and your bank | Their form, their deadline, their internal policy. Usually days or weeks. |
| Do I have, or can I get, a U.S. identifying number? | The U.S. government | Whether you are a U.S. citizen or otherwise eligible for a Social Security number. Months, sometimes. |
| Do any U.S. tax years need attention? | The U.S. tax rules, applied to your own figures | Your income by year, your accounts, your status. Independent of the other two. |
They are genuinely independent. You can answer the bank honestly while your number is still being applied for. You can have a number and owe nothing. You can owe nothing and still have a reporting obligation. Treating the bank's deadline as the deadline for all three is what turns a form into a panic.
1. What your bank is asking for
Almost always a self-certification: a statement of your tax residence and status, on the bank's own form or on a U.S. one. Which U.S. form depends on the answer, and this is worth getting right because the two are opposites.
| Form | Who it is for | What it says |
|---|---|---|
| W-9 | U.S. persons | I am a U.S. person, and here is my U.S. taxpayer identification number. |
| W-8BEN | Non-U.S. persons | I am not a U.S. person, and here is where I am tax-resident. |
Answer accurately. If you do not yet know whether you are a U.S. person, the honest answer to your bank is that you are establishing it — not a guess in either direction. Most institutions have a process for exactly that, because it is common. What you should not do is certify something you do not know to be true; both forms are signed statements.
2. The identifying number
If the answer is that you are a U.S. person, the bank needs a U.S. taxpayer identification number. Which one you need is not a choice — it follows from your status, and getting this backwards is the expensive mistake on this page.
- A U.S. citizen is eligible for a Social Security number (SSN). That is the number, and it is applied for through the Social Security Administration — usually via a U.S. embassy or consulate when you are abroad. It is not fast, but it is the correct route.
- An ITIN is for people who are NOT eligible for an SSN. That is what the form's own instructions say. A citizen who applies for an ITIN is applying for the wrong number, and the application should be rejected.
Tell your bank the application is in progress. A number that does not exist yet cannot be supplied, and that is a normal state of affairs rather than a failure to comply.
3. Whether any tax years actually need attention
This is the only one of the three that is a tax question, and it is the one the letter cannot answer. U.S. citizens and lawful permanent residents file based on worldwide income against a threshold that depends on the year, the filing status and age — not on where they live and not on what a bank reported.
Two things follow. First, a year below the threshold generally needed no return, and no bank letter changes that. Second, the account-reporting rules are separate from the income rules: the FBAR turns on the combined peak balance of your non-U.S. accounts, so it can apply in a year with almost no income. That is why "I earn very little" is not a complete answer to this letter.
If you are not sure you are American at all
This is common, and it deserves to be treated as its own question rather than assumed away in either direction. A U.S. birthplace usually means U.S. citizenship, but not always. Citizenship through a parent depends on that parent's own citizenship, their physical presence in the United States before your birth, and the law in force on the date you were born — which has changed several times.
Neither your bank nor this site can settle it. It is determined under U.S. law and confirmed by the State Department, typically through a consulate. Until it is settled, do not buy tax services premised on an answer nobody has given you yet.
Work out which part you actually need
If your status is settled and the open question is which years and forms apply to you, that is what the paid diagnostic answers — year by year, against each year's own published threshold. If your status is not settled, start with the accidental-American guide instead; it costs nothing and it is the right first step.
A reasonable order to do this in
- Read what the bank actually asked for, and note its deadline. It is usually a self-certification, not a demand for a number you do not have.
- Settle your status if it is genuinely open. Everything else depends on the answer, and no tax work is worth buying before it.
- Reply to the bank accurately, including "in progress". An honest incomplete answer is better than a confident wrong one on a signed form.
- Start the correct number application — an SSN if you are a citizen, and an ITIN only if you are genuinely not eligible for an SSN.
- Then, separately, look at the tax years. Check your income for each year against that year's threshold, and check your accounts against the FBAR rules. These are two different tests.
- Get help for the part that is actually hard, which is usually the year-by-year question rather than the form the bank sent.
Where Atamatax fits, and where it does not
We can help with the third question: which years appear to have needed a return, which forms follow, and what the deadlines are. We do not contact your bank, cannot influence its decisions, do not obtain SSNs or ITINs for you, and do not determine anyone's citizenship. Those first two problems are yours and the government's; we are only useful on the third.
Not sure which part applies to you?
Three questions, then a suggestion
This points you at the right next step. It is not a tax assessment and cannot tell you whether you have to file — that depends on figures these questions do not ask for.
Answer all three to see a suggestion.
Authorities cited
- IRS — FATCA reporting for individuals — IRS — Summary of FATCA reporting for U.S. taxpayers
- Form W-9 — Form W-9 — Request for Taxpayer Identification Number and Certification
- IRS — Taxpayer Identification Numbers — IRS — Taxpayer Identification Numbers (TIN): which number applies to whom
- Form W-7 — Form W-7 — Application for IRS Individual Taxpayer Identification Number (ITIN)
- IRC §6012 — IRC §6012 — Persons required to make returns of income
- 31 U.S.C. §5314 — 31 U.S.C. §5314 — Statutory basis for the FBAR (foreign financial account reporting)
- FinCEN Form 114 (FBAR) — Report of Foreign Bank and Financial Accounts (FBAR)
- IRS · US citizens and resident aliens abroad — IRS — U.S. citizens and resident aliens abroad (filing requirement and automatic extension)
Primary sources (Cornell Legal Information Institute for the US Code and CFR; IRS.gov for forms, procedures, and treaty documents). This page is general information, not individualized tax or legal advice.
Atamatax provides tax preparation support and educational resources. This website does not constitute legal or tax advice.