The Common Reporting Standard, usually shortened to CRS, is an information-sharing system. It requires financial institutions in participating jurisdictions to identify customers' tax residences, report specified financial-account information to their local tax authority, and support annual exchange with other participating tax authorities.
CRS does not decide where a person is tax resident, calculate a tax bill, or prove that tax is due. Its practical effect is simpler: the information given to a bank or broker can travel further than many internationally mobile account holders expect.
Who this is for
This guide is for people who have moved country while keeping bank, brokerage, custody or investment accounts elsewhere. It is particularly relevant where a reader has homes or working ties in more than one jurisdiction, has recently changed address, remains connected to the UK, becomes resident in Portugal or another EU country, or holds accounts through a company, trust or foundation.
It is also useful before opening a new account. A tax-residence self-certification can look like a routine form, but it sits at the junction of domestic residence law, account classification and automatic information exchange.
Why this matters
Most CRS problems are not dramatic offshore schemes. They are ordinary mismatches: a bank still holds an old address; a move happened partway through a tax year; one adviser applied a treaty tie-breaker while a bank asked for every domestic-law residence; or an account-owning entity was classified without considering its controlling persons.
Those mismatches create questions. A tax authority may receive an account balance or income figure that does not line up neatly with a return. A bank may ask for a new self-certification. An account opening can stall while tax identification numbers or residence evidence are checked.
The response is not secrecy or panic. It is a consistent record of where the person was resident under each country's domestic law, what was disclosed to each institution, and how the reported account figures connect to tax filings.
Key definitions
CRS is the OECD standard for due diligence, financial-account reporting and automatic exchange between participating jurisdictions.
Tax residence is a legal status determined under each jurisdiction's domestic law. It is not automatically the same as citizenship, a residence permit, a mailing address or the country where a bank account is held.
Self-certification is the account holder's declaration to a financial institution about matters including tax residence and tax identification numbers. The institution checks whether that declaration is reasonable against the information it holds.
Reportable account is a financial account within the standard's scope that is linked to a reportable person or, in some cases, an entity with reportable controlling persons.
What CRS can report
The OECD's consolidated CRS text sets out the account information and due-diligence framework. Depending on the account and institution, reported fields can include the account holder's name, address, jurisdictions of tax residence, tax identification numbers, date and place of birth, account number, reporting institution, year-end balance or value, and specified gross amounts such as interest, dividends, other income or disposal proceeds.
The figures are reporting fields, not a complete tax computation. Gross proceeds do not reveal acquisition cost. An account balance does not show whether funds are capital, income, a loan or a transfer between accounts owned by the same person. A report can therefore be correct while still needing context before anyone can understand the tax treatment.
Within the EU, DAC2 provides the legal framework for annual exchange of financial-account information between member states. The European Commission lists categories including account balances and specified income and proceeds.
Portugal's tax authority also explains that it receives information about foreign income obtained by Portuguese residents and sends corresponding information abroad. That is why a Portuguese move should be reflected not only in immigration paperwork, but also in the records held by banks, brokers and tax advisers.
Tax residence comes before the bank form
The bank does not invent tax residence. The OECD tax-residency portal makes the starting point clear: each jurisdiction defines residence under its own domestic law, and a person can be resident in more than one jurisdiction at the same time.
That distinction matters after a move. A person may arrive in Portugal in May, retain a UK home, continue UK workdays and satisfy residence tests in both countries for part or all of the year. A tax treaty may then allocate treaty residence for particular treaty purposes. That conclusion does not automatically rewrite every domestic filing duty or every account-reporting answer.
For the UK implementation, HMRC's CRS residence manual says that, from 1 January 2026, an account holder completing a self-certification cannot rely on a treaty tie-breaker to declare only one jurisdiction. All jurisdictions of tax residence under domestic law must be declared. HMRC also says financial institutions are not expected to carry out an independent legal analysis of tax residence.
This is a reporting point, not a universal statement about treaty relief. The practical lesson is that "treaty resident in Country A" and "only Country A belongs on every bank form" are not interchangeable conclusions.
For a fuller separation of these labels, read Tax Residence, Domicile and Treaty Residence: What Each One Means.
The cross-border decision map
A reliable CRS file can be built in six steps.
1. Map residence by calendar and tax year
Record move dates, homes, workdays, family location and other facts used by each relevant domestic test. Keep immigration residence separate. Where two countries can claim residence, identify whether treaty analysis is needed and what that analysis changes.
Readers leaving Britain can place this alongside Leaving the UK: A Practical Exit-Planning Timeline, which covers the evidence needed for the UK Statutory Residence Test and the separate questions raised by split-year and temporary non-residence rules.
2. Inventory financial accounts
List banks, brokers, custodians, cash-value insurance products and entity-held investment accounts. Record the legal account holder, institution country, account number, current address, tax residences on file and the date of the latest self-certification.
3. Identify changes of circumstances
A new home address, tax identification number, residence permit, telephone number or other information can make an old self-certification unreliable. The institution may request an update. Account holders also need a process for telling every relevant institution rather than updating only the bank used for day-to-day spending.
The broader banking consequences are covered in Why Banking Gets Harder as Your Life Gets More International.
4. Check entity classification
An account owned by a company, partnership, trust or foundation is not answered by writing the founder's personal residence on every form. The entity's residence and CRS classification matter. For some passive entities, the institution may also identify and report controlling persons. Legal ownership, control and tax residence need to be mapped separately.
5. Reconcile reported figures with returns
Year-end statements, interest, dividends and gross disposal proceeds can be compared with the relevant returns and supporting schedules. Differences are not automatically errors, but they should be explainable: timing, joint ownership, exchange rates, transfers, cost basis and tax-year differences can all matter.
6. Preserve the evidence
Keep copies of self-certifications, residence analyses, tax identification numbers, correspondence, account statements and adviser conclusions. A dated file is more useful than trying to reconstruct the answer after a bank or tax authority asks a question.
A composite move from the UK to Portugal
Consider a British founder who moves to Portugal in June 2026. She keeps a UK current account, a UK brokerage portfolio and an investment company account. Her spouse arrives in August. The family keeps its UK home until December, and the founder returns for board meetings.
The Portuguese residence permit does not settle either person's tax residence. Their day counts, homes, work and other ties need separate domestic-law analysis. They may not reach the same answer because they moved on different dates and have different working patterns.
Each financial institution can hold a different snapshot. The current account may have the Portuguese address, the broker may still show the UK address, and the company account may be waiting for an entity classification update. If domestic law makes the founder resident in both countries, the UK CRS self-certification point described above may require both residences even where a treaty conclusion is also available.
No tax outcome can be inferred from those facts alone. The example shows the coordination task: residence analysis, account data, entity classification and tax filings must describe the same real timeline.
If the move is connected with Portuguese incentives, IFICI Explained: Portugal's Tax Incentive in Plain English explains why regime eligibility is a separate question from CRS reporting.
What can go wrong
Only the mailing address changes. A new address is entered, but the tax-residence fields and tax identification number remain stale.
Treaty residence is treated as the only residence for every purpose. A treaty conclusion may be relevant to tax allocation without permitting the account holder to omit a domestic-law residence from a self-certification.
The report is mistaken for a tax bill. Gross proceeds or balances are copied into a return without checking the tax category, ownership, basis, currency or applicable tax year.
An entity account is treated like a personal account. The entity classification and controlling-person analysis are skipped or answered inconsistently across institutions.
Only one institution is updated. The household's main bank is current, but older brokers, private banks, insurance providers or custodians retain the previous profile.
The file exists only in advisers' inboxes. When an adviser changes, the family cannot produce the self-certification, residence memo or explanation behind a reported number.
Questions to ask qualified advisers
- Under domestic law, which jurisdictions treated each family member as tax resident during the relevant calendar and tax years?
- Could more than one country claim residence, and what does any applicable treaty change?
- Which residences and tax identification numbers belong on each current self-certification?
- Has a move or other change of circumstances made an existing certification unreliable?
- Which accounts are personal, joint or entity-held, and are controlling persons reportable?
- How do the balances, income and gross proceeds likely to be reported reconcile with tax returns and underlying records?
- Are any institutions still holding an old address, nationality assumption or incomplete tax identification number?
- Who owns the annual process for checking the account inventory after another move?
FAQ
Does CRS mean a tax authority can see every transaction?
Not as a universal rule. CRS specifies reportable account and financial fields, which can include balances and gross income or proceeds. It is not a complete transaction ledger for every account, and the exact fields depend on the account type and applicable implementation.
Does a residence permit make someone tax resident for CRS?
Not automatically. Domestic tax law determines tax residence. Immigration permission, citizenship and the right to reside can be relevant facts, but none is a universal substitute for the domestic residence test.
Can someone list only their treaty residence?
That depends on the reporting implementation and timing. For UK CRS self-certifications from 1 January 2026, HMRC says all domestic-law tax residences must be declared rather than using a treaty tie-breaker to state only one.
What happens when a bank form is wrong?
The appropriate correction depends on the facts and institution. A reader can retain the old form, obtain the residence analysis, contact the institution through its tax-document process and make sure related returns and records explain the same timeline. Qualified tax advice is appropriate where residence or reporting is uncertain.
Is CRS the same as FATCA?
No. Both concern financial-account reporting, but FATCA is a US regime with its own status, documentation and reporting rules. CRS is the OECD multilateral standard implemented by participating jurisdictions.
Content on Wealth Nomad is for general information and education only. It is not financial, investment, legal, tax, immigration, or accounting advice. Rules vary by jurisdiction and personal circumstances. Always speak to qualified advisers before making decisions.
