Asahi Shimbun Digital, Security NEXT and Mainichi Shimbun Digital reported a data breach at NTT Docomo (Japan) on 4 November 2026, and it has been confirmed. It affected 300,000 customers.
What we know as of
Status
Confirmed.
People affected
300,000 customers.
What was exposed
Phone numbers, Dates of birth, Names and Addresses.
When
First reported 4 November 2026.
How
Hacking.
NTT Docomo’s record
No earlier breach on record under this name.
Not known yet: when it began and who was behind it. This page is updated as notices and statements come in.
Every fact above has its source below. Journalists: free to quote with credit (“Privacy Unpacked data breach tracker”, with a link to this page and the date); the figures can move. Follow this breach (feed) · Every major breach · Ask us for a figure
People affected
300,000customers
Reported
4 November 2026News report and 2 more
What was exposed 4
Phone numbers
Dates of birth
Names
Addresses
How it happened
How
Hacking Unauthorized accesssourceOur translation from Japanese不正アクセス
Confirmed by NTTドコモ: NTT Docomo announced on the 5th that unauthorized access occurred to "Docomo Online Shop" and "My docomo" where procedures such as contract changes are carried out, and that customer information of up to approximately 300,000 records was leaked.Our translation from JapaneseNTTドコモ は5日、「ドコモオンラインショップ」と契約変更などの手続きをする「My docomo」に 不正アクセス があり、最大約30万件の顧客情報が流出したと発表した。
Confirmed by NTTドコモ: Regarding the issue of a leak of 300,000 pieces of customer personal information, a press conference was held in Tokyo, where President Yoshiaki Maeda apologizedOur translation from Japanese顧客の個人情報30万件が漏えいした問題で、東京都内で記者会見を開き、前田義晃社長が謝罪した
News reports are read by an AI model; every fact taken from an article was checked word for word against it, and anything it could not find was dropped. · Corrections and changes
Questions about the NTT Docomo breach
Was NTT Docomo hacked?
Asahi Shimbun Digital, Security NEXT and Mainichi Shimbun Digital reported a data breach at NTT Docomo (Japan) on 4 November 2026, and it has been confirmed. It affected 300,000 customers. How it happened, by the sources: hacking.
What data was exposed in the NTT Docomo breach?
Phone numbers, Dates of birth, Names and Addresses, by the notices and reports on this page.
How do I know if I was affected?
Organisations normally tell the people whose data was involved, by letter or email, and that notice says what of yours was in it. We cannot look up individual people. If you got a notice, check that it is real, then follow the steps on this page.
Is there a NTT Docomo data breach settlement?
No settlement open for claims is on record for NTT Docomo as of 15 November 2026. Every open settlement is listed with its deadline.
Is a letter, email or text about the NTT Docomo breach real or a scam?
A real notice names the breach, says what data was involved and never asks for a password, a code or a payment. Criminals often send fake notices after a breach is in the news. Do not use links or phone numbers in the message: go to NTT Docomo’s own site, or check the letter here.
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