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My Number and Banking: Requirements and Rules

Japanese banks collect your My Number because tax and account-management statutes direct them to, not because each branch invented its own rule.12 This article covers the requirement side: the collection duty, legacy accounts, the FATCA and CRS exchange behind it, refusal effects, and purpose limits.13

Confirm current details with official sources

Procedures, fees, and requirements can change. Confirm current details at the National Tax Agency site, the Digital Agency site, or your bank. This article is general information, not tax advice; for cross-border residency questions, consult a licensed tax accountant (zeirishi).

Overview​

My Number use at banks started in January 2016 to tie personal information held across agencies to the same individual.1 The same number serves three layers that are often conflated: statutory tax reports, voluntary deposit-account numbering, and the benefit-account registry.425

For the counter-level mechanics of what to bring at account opening, the companion banking article walks through documents, online verification, and FATCA and CRS forms step by step. Read that one before visiting the branch; read this one to understand why the bank asks at all.

The collection duty since 2018​

From January 2018 banks ask new openers of yen savings and similar deposit accounts to notify their My Number.16 Bank forms cite the underlying statutes directly: Income Tax Act Article 224(1) and its Enforcement Order for mutual-fund accounts, and the wire-transfer statement rules for overseas transfers.7

Mutual-fund general and special accounts, Maruyu changes, and overseas wire transfers each trigger statutory reports to the tax office on the instrument's own basis.71 Reporting follows the transaction or account event rather than a single annual date.8

New accounts from 2018 onward​

SMBC Trust Bank states the request expressly on two legal bases at opening: the amended Number Use Act and the Account Management Act for depositor-willed numbering.6 Other banks use shorter wording, but the underlying structure is the same nationwide.

For ordinary yen savings, the bank phrases the request as cooperation: customers "may be asked" to notify the number.1 Numbering proceeds only on the holder's notification, so a deposit account is never numbered silently.2

The three mandatory backward-looking categories​

Three narrow categories are framed as legally required notifications: deposit accounts opened by the end of December 2015 where the holder makes or receives an overseas transfer after January 2022, mutual-fund accounts opened by the end of December 2015, and corporate accounts opened by the end of December 2015.1

Ordinary yen-savings and similar deposit accounts sit outside that mandatory set. They live in the cooperation-request layer described above.12

The legacy-account push​

Holders of older accounts may later receive a My Number notification request by mail, email, or in-app notice.1 This follow-up is normal because numbering needs the holder's filing, so banks re-ask holders who never filed one.2

Verify mailed or in-app number requests through the official channel

A later request on a long-held account is routine follow-up rather than proof of fraud by itself. Contact the bank through its official site or branch details before acting on any link in the message.21

From April 2025, procedures under both the Account Management Act and the Account Registration Act can also be filed via MynaPortal by card holders (as of 2025; confirm current availability with the Digital Agency).5

My Number as the FATCA/CRS key​

Japan committed to automatic exchange of financial-account information with treaty partners and uses My Number as the linkage key. Under the Common Reporting Standard, reporting institutions report in-scope account information to the district director yearly, and the National Tax Agency exchanges it under tax-treaty provisions.93

The CRS came into effect in Japan on January 1, 2017, and the first automatic exchange followed by September 2018 across 102 committed jurisdictions (figures as of April 2018; confirm current participation with the National Tax Agency).103 The dataset covers name, address, residence jurisdiction, foreign Taxpayer Identification Number, account balance, and annual interest and dividend totals.3

CRS self-certification at opening​

For new accounts opened on or after January 1, 2017, the holder submits a self-certification (自己証明, jiko shōmei) stating name, address, residence jurisdiction, and foreign TIN.9 Holders of pre-2017 accounts may voluntarily submit one for pre-existing accounts.9

Where the declared jurisdiction is Japan, the holder writes "Japan" and no My Number is entered on the CRS form itself.9 Where it is a foreign jurisdiction, the foreign TIN must be stated.9

FATCA and US persons​

The Foreign Account Tax Compliance Act targets US persons globally: foreign financial institutions report assets held by US account holders or face withholding on withholdable payments.11 Japanese banks therefore identify Specified US Persons at opening and route them to a dedicated substitute W-9 rather than the IRS form itself.11

The US-Japan intergovernmental framework channels this reporting through the Japanese authorities and the tax convention, so compliant institutions are not required to terminate recalcitrant accounts or impose passthrough withholding.8

Refusal consequences​

Declining the voluntary deposit-numbering notification carries no individual monetary penalty in any bank notice fetched for this article; the standard wording is appreciation of understanding and cooperation (penalty posture inferred from the absence in bank and Digital Agency notices, not from a penalties schedule).12 No numbering occurs without notification.2

The required layers behave differently. CRS self-certification at new-account opening is a required form step, distinct from voluntary numbering.109 Where identity verification or required tax-residency paperwork stays incomplete, banks may restrict services under anti-money-laundering and tax-reporting duties.10

Skipping the tax-residency form is the refusal that bites

The voluntary numbering notice and the CRS self-certification arrive in the same envelope but have different weights. Complete each form the bank asks rather than assuming one covers the other.910

Purpose limits and privacy​

Numbering alone does not send balances to the state.2 The government can confirm a depositor's account information only when conducting necessary financial or tax investigations for social-security purposes under laws and regulations.2

Numbering instead enables later lookups. Heirs can inquire about a decedent's numbered accounts at one institution during inheritance, and holders can inquire after a disaster, in each case presupposing the number was already registered on those accounts.52

Good to know​

Numbering your account is not registering a benefit account​

The public-money receiving-account registry runs under a different act and registers one account per person with the state for pensions, child allowance, and tax refunds.25 Registering a benefit account does not by itself number the deposit account, and numbering does not register the benefit account.2

Notifying the number does not transmit your balance​

Defined tax-reporting datasets flow on fixed schedules, but the numbering notification itself moves no balance data.23 If privacy is the worry, aim it at the correct layer: the statutory reports, not the numbering request.2

See also​

References​

Footnotes​

  1. SMBC Trust Bank PRESTIA. FAQ No. 211 "For which transactions is My Number required?", updated 2026-01-23. https://faq.smbctb.co.jp/faq/show/211?site_domain=smbctben ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11

  2. Digital Agency, Government of Japan. "FAQ: Deposit Account Numbering System," last updated 2026-03-31. https://www.digital.go.jp/en/policies/mynumber_faq_09 ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10 ↩11 ↩12 ↩13 ↩14 ↩15

  3. National Tax Agency (NTA). "Proper and Fair Taxation and Collection" (2018 annual report excerpt; CRS exchange, wire records). https://www.nta.go.jp/english/Report_pdf/2018e_06.pdf ↩ ↩2 ↩3 ↩4 ↩5

  4. Digital Agency, Government of Japan. "Deposit account numbering system" (overview), last updated 2025-03-31. https://www.digital.go.jp/en/policies/numbering-on-accounts ↩

  5. SMBC Trust Bank PRESTIA. "New Act Regarding the My Number System (2)" (Account Management Act and Account Registration Act procedures from April 2025). https://www.smbctb.co.jp/en/news/2025/news_071425_01.html ↩ ↩2 ↩3 ↩4

  6. SMBC Trust Bank PRESTIA. "Open an Account: Requirements / Request for Notification of your Individual Number." https://www.smbctb.co.jp/en/openaccount/application.html ↩ ↩2

  7. SMBC Trust Bank PRESTIA. "Notification of Individual/Corporate Number" request form and ID guide (statutory bases and accepted documents). https://www.smbctb.co.jp/en/support/updatingprofile/pdf/mynumber.pdf ↩ ↩2

  8. National Tax Agency. Joint Statement US-Japan FATCA framework press release. https://www.nta.go.jp/english/release/10.htm ↩ ↩2

  9. National Tax Agency (NTA). Leaflet "To persons who will open financial accounts etc." (CRS self-certification outline), PDF. https://www.nta.go.jp/taxes/shiraberu/kokusai/crs/pdf/0021012-107_02.pdf ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7

  10. Mizuho Bank. "Common Reporting Standard (CRS)" notice and instructions (CRS effective 1 January 2017 in Japan). https://www.mizuhogroup.com/bank/crs ↩ ↩2 ↩3 ↩4

  11. U.S. Internal Revenue Service. "Foreign Account Tax Compliance Act (FATCA)." https://www.irs.gov/businesses/corporations/foreign-account-tax-compliance-act-fatca ↩ ↩2