FATCAThe US rules that make banks outside the US report accounts held by US persons, such as US citizens and green card holders. and CRS (Common Reporting Standard)The global system where banks report account holders' details and balances to their tax office, which passes them to the country where the holder is tax resident. are information-sharing systems. Your bank asks where you're tax resident and, for FATCA, whether you're a US citizen, then handles the reporting to the tax authorities 1 2. The UK's CARF (crypto reporting)The crypto version of CRS: exchanges and crypto service providers report users' transactions to tax offices, which share them across borders. and amended CRS rules took effect on 1 January 2026 3. Moving abroad doesn't switch any of this off.
Do FATCA and CRS apply to me?
If you hold accounts, these rules may well apply to you, because they apply to financial institutions. Check your own position with your bank or an adviser. Both are rules that make financial institutions collect your tax details and pass account information to tax authorities, and the UK applies both 5.
Let's unpick the jargon.
- FATCA stands for the Foreign Account Tax Compliance Act. It's the US one, which is why your bank asks if you're a US citizen 1.
- CRS stands for the Common Reporting Standard. It's built around the country where you're tax resident 1.
- CARF is the Cryptoasset Reporting Framework, the newest piece. The UK's CARF and amended CRS rules took effect on 1 January 2026 3. The regulations bringing crypto providers with a UK connection into reporting came into force the same day 4.
HMRC publishes guidance notes on the UK's FATCA and CRS duties for financial institutions, updated July 2026 5.
Three acronyms and one form. Welcome to banking.
What does my bank ask me, and what does the form actually decide?
When you open an account, your bank will usually ask you to fill in a Self-certificationThe form a bank asks you to fill in saying where you're tax resident, so it knows what to report and to whom.. That's a short form where you state your own tax details. It doesn't decide where you pay tax, but the bank relies on it 1.
| Field on the form (as of October 2026) | Why it's asked |
|---|---|
| Name | Identifies you 1 |
| Address | Part of your record 1 |
| Tax residenceThe country that treats you as living there for tax purposes, and so can tax your worldwide income. Each country sets its own rules; your passport doesn't decide it. country or countries | The basis for CRS reporting 1 |
| Tax identification number(s), where applicable | Links you to your record in that country 1 |
| US citizenship | Needed for FATCA 1 |
Source: HMRC International Exchange of Information Manual 1.
Notice the "(s)" on country. The form asks for your tax-residence jurisdiction(s), so it allows for more than one 1.
The question people trip over is the tax-residence one. Tax residence isn't necessarily the same as your nationality, your immigration status, where you get post or where you keep a bank account 1. The form is asking about tax residence under the relevant rules 1.
HMRC's guidance also says a self-certification isn't, on its own, a ruling on your tax residence or what you owe 1. Ticking "Portugal" doesn't make you Portuguese for tax. The residence rules do that. So answer from those rules, not from your gut.
What does HMRC receive, and who does it share it with?
Your UK bank or crypto provider checks your details and reports to HMRC. The checking and reporting duties sit with the financial institution, not the account holder 2. For crypto, providers with a UK connection do due diligence, report user and transaction information to HMRC, and notify users 4.
HMRC's own guidance calls the CRS side the "automatic exchange of financial account information" 5. Note the word "exchange". Information is meant to move between countries, not just sit with HMRC. The guidance notes set out exactly which details are reported, and how 5.
For crypto, the UK reports users who fall under CARF's international exchange rules. It has also extended reporting to UK-resident users, under the Finance Act 2026 6.
The form isn't, by itself, a ruling on your tax residence or what you owe 1, but it is the information your bank relies on and reports from 2. Get it right.
What changes when I move abroad?
Moving abroad can change your tax residence, but your bank only knows what's on its records. If a UK bank still holds your old address or old residence declaration, it may ask you to confirm or replace it 2.
The rule is that a self-certification stays valid unless the bank knows, or has reason to know, that it's wrong or unreliable 2. Once it can't rely on the form, it has to get either a valid new one or a reasonable explanation for the original, with documents where appropriate 2.
Remember, the form asks about tax residence under the relevant rules, not where you receive mail or where you hold a bank account 1. If you're unsure whether you've stopped being UK resident, take advice before you fill in the form.
Where are the grey areas?
Most of FATCA and CRS is settled, dull and non-negotiable, like most forms with an acronym on top. There's one real grey area worth knowing about, and it's the one people ask about most.
- Your passport isn't your tax residencesettled
Why it's greythe form asks where you're tax resident under the relevant rules, not your nationality or immigration status [1]
What it could meanput your real tax residence on it, whichever passport you hold
- The form doesn't decide your tax, but it has to be rightsettled
Why it's greyit isn't a ruling on your tax residence or what you owe, but it needs to be right [1]
What it could meanif the bank can no longer rely on it, it must get a valid new self-certification or a reasonable explanation from you [2]
- Using residence or citizenship by investment to look tax resident somewhere elseaggressive
Why it's greythe Tax Justice Network, an advocacy group, argues these schemes could let someone present a low-tax country as their tax residence, so the country where they really live receives no report [7]. That's an advocacy organisation's argument, not an official finding of evasion [7]
What it could meana bank can keep relying on your form unless it knows, or has reason to know, that it's incorrect or unreliable [2]. Misstating where you live on the form is a bad idea whatever the critics say
Grey areas turn on the details: where you live, how the money moves and what paperwork you keep. On a free 30-minute call we look at your own situation and tell you plainly how strong your position would be, before you commit to anything.
What if I filled the form in wrong, or the account is closed?
Tell the bank and ask how to submit a corrected self-certification. An old form stays valid unless the bank knows or has reason to know it is incorrect or unreliable 2, so don't count on a mistake being picked up for you. If the error may have affected what was reported, take advice.
The bank carries the reporting duty 2, but a wrong answer is still not harmless for you. The bank's checks rest on the self-certification you give it, and it must act if it knows or has reason to know that form is incorrect or unreliable 2.
- 1Contact the banksay you think your tax-residence details are out of date or wrong [2]
- 2Identify the formask which self-certification they hold and what it says
- 3Ask for the processfind out how they want a corrected self-certification submitted [2]
- 4Send the new formgive your current tax residence and tax number(s) [1]
- 5Keep copiessave the form, your covering note and the bank's reply
If the account has already been closed, it's unclear how the bank will treat a correction, so contact it anyway and ask what it needs. Consider taking advice, especially if the error may have affected what was reported. Keep copies of whatever you send and whatever comes back. Paperwork is dull until the day you need it.
I'm a US person, or I'm tax resident in two countries. What then?
If you're a US citizen, your bank will ask about that separately from where you're tax resident. Under FATCA, the institution also needs to establish whether you're a US citizen, on top of the usual self-certification details 1. The form also asks for your tax-residence jurisdiction(s), so it allows for more than one 1.
Two questions, two answers. Your passport answers the first one. The residence rules answer the second, because tax residence isn't necessarily the same as nationality 1. So a US citizen living in Portugal still ticks "yes" to US citizenship and then gives their tax residence under the relevant rules. Passports don't get a vote on the second box.
- You hold US citizenship and bank in the UK or elsewhere [1]
- You meet the residence rules of more than one country at the same time [1]
- You're not sure which countries to list as your tax residence
- You hold one non-US nationality and are clearly resident in one country
How Dual residence and tie-breaker testsWhen two countries both treat you as resident. A tax treaty between them usually has tie-breaker tests to decide which one wins. gets settled between two countries depends on their own rules. That isn't something the bank form decides. A self-certification isn't, by itself, a ruling on your tax residence or what you owe 1. If you think you may count as resident in two places, get a tax adviser to look at both countries' rules before you fill anything in. Then give every bank the same answer.
What is the new crypto reporting (CARF), and when does it start?
The Cryptoasset Reporting Framework (CARF) is the crypto counterpart to CRS. Under regulations that came into force on 1 January 2026, crypto providers with a UK connection do due diligence, report user and transaction information to HMRC, and notify users 4. The UK's CARF and amended CRS rules took effect on 1 January 2026 3.
The UK law behind it is a set of 2025 regulations (SI 2025/744). They require crypto providers with a UK connection to check who their users are, report user and transaction information to HMRC, and tell users they're doing it 4. So if your exchange suddenly wants your tax residence and tax number, it's not being nosy for fun. It's being nosy by law.
The first CARF reporting period covers 1 January to 31 December 2026, and the report must be submitted to HMRC by 31 May 2027 3. That means this year's activity falls within the first reporting period.
There's a UK twist, too. The UK has extended CARF reporting to UK-resident crypto users, as well as users reportable to other countries, through the Finance Act 2026 6. So this isn't only about expats. If you live in the UK and use a covered provider, your details can be reported to HMRC as well 6.
What to do: answer your provider's self-certification questions accurately. Keep your own records of what you bought, sold and when.
What should I do now to stay compliant?
Staying compliant mostly means knowing your tax residence and telling every bank and crypto provider the same, accurate thing. Most of the work is a few forms and a short checklist.
FAQ
Does a bank's self-certification form decide where I pay tax? No. HMRC guidance says a self-certification isn't, by itself, a ruling on your tax residence or what you owe 1. The residence rules decide that.
What if I made a mistake on the form? A form stays valid unless the bank knows or has reason to know it's wrong 2. So tell the bank, ask how to submit a corrected self-certification, and keep copies.
When does UK crypto reporting (CARF) start? It took effect on 1 January 2026 3. The first report covers calendar year 2026 and is due to HMRC by 31 May 2027 3.
Who is responsible for the reporting, me or the bank? The bank carries the checking and reporting duties 2. It reports based on what you told it, though, so an inaccurate form still matters for you.
Is my tax residence the same as my nationality? No. Tax residence isn't necessarily the same as your nationality, immigration status, where you get mail or where you bank 1.
Does CARF only affect people living abroad? No. Under the Finance Act 2026, the UK also reports UK-resident crypto users 6.
