UPDATE — 6 November 2026, 20:00 IST: NTT Docomo president Yoshiaki Maeda said on Friday that the leaked data includes identity verification document numbers and bank account numbers with account holders' names — alongside names, addresses, dates of birth, phone numbers and subscription plan details. Former subscribers are also affected. The good news: no credit card information was compromised. Docomo plans to pay compensation to affected people, with the scope of recipients to be decided later. The number of affected records is still up to about 300,000, the online shop and My docomo portal remain suspended, and no resumption time has been given. (Sources: Jiji Press via Nippon.com, 6 November 2026; NTT Docomo third report, 6 November 2026, 18:00 JST.)
UPDATE — 6 November 2026, 09:15 IST: NTT Docomo says its 5G standalone service is back to normal. Voice calls, data and texts on 5G SA were unstable from about 11:18 a.m. JST on Thursday 5 November until around 1:20 a.m. JST on Friday 6 November — roughly 14 hours. Docomo says the cause was congestion in switching equipment serving 5G SA subscribers, and its investigation found no signs of unauthorised access or a cyberattack. Other 5G and 4G services, MVNO networks and emergency calls were unaffected. Separately, the online shop and My docomo portal remain suspended after the breach that exposed personal information linked to up to 300,000 customer accounts — Docomo says no further leaks have been detected, but has given no time frame for resuming those services. (Source: Kyodo News, 6 November 2026.)
Image: NTT Docomo's Yoyogi Building in Tokyo, which houses switching equipment for the carrier's mobile network. Image: Wikimedia Commons / Basile Morin, CC BY-SA 4.0
📌 Key Highlights
- NTT Docomo's 5G standalone (5G SA) service — voice calls, data and SMS — has been unstable nationwide since around 11:18 a.m. JST (7:48 a.m. IST) on Wednesday 5 November 2026.
- Other 5G and 4G services are unaffected, and emergency calls to 110 and 119 are working normally, the carrier said.
- The cause is still under investigation, and Docomo says it has found no signs that a cyberattack caused the disruption.
- Workaround from Docomo: switch to 4G in your phone's network settings, then restart the phone or toggle airplane mode on and off.
- Separately, Docomo suspended its online shop and My docomo site from about 1:05 a.m. JST after finding a high possibility of unauthorised access to its servers — no connection to the outage has been disclosed.
What happened in the NTT Docomo outage?
NTT Docomo, Japan's largest mobile carrier, said on Thursday that customers across Japan were having trouble using its mobile services. The problems are concentrated on its standalone 5G service, known as 5G SA — the high-speed, high-capacity network that handles calls, data and text messaging for customers on that plan. The glitches started at around 11:18 a.m. local time, and by the afternoon the carrier was still investigating the cause, with no restoration time announced.
The disruption was still being reported as ongoing in the latest wire updates on Thursday evening in Japan, with the Japan Times reporting the glitches at 7:19 p.m. JST (3:49 p.m. IST) and Kyodo News updating its report at 6:42 p.m. JST (3:12 p.m. IST). That makes this a live, unresolved outage at one of the world's biggest mobile networks — not a brief blip.
Which services are affected — and which still work
The good news is that the outage is limited. Docomo was clear that only its 5G standalone service is unstable. Everything else on its network is running normally, which is why the carrier's own advice is to drop back to 4G.
| Service | Status on 5 Nov 2026 |
|---|---|
| 5G standalone (5G SA) — calls, data, SMS | Unstable nationwide since ~11:18 a.m. JST |
| Other 5G services | Working normally |
| 4G services | Working normally |
| Emergency calls (110 / 119) | Working normally |
| Docomo online shop / My docomo | Suspended since ~1:05 a.m. JST (separate issue) |
Illustrative image: a Sony Xperia XZ handset sold by NTT Docomo. Image: Wikimedia Commons / Mytho88, CC BY-SA 4.0
The separate online-shop suspension
Earlier the same day, Docomo suspended its online shop and the My docomo members' site after determining there was a high possibility of unauthorised external access to its servers. The suspension began at around 1:05 a.m. JST, leaving customers unable to use those services to sign up for mobile plans, check bills or make contract changes. Docomo said it was investigating the cause, and it has not disclosed any connection between the possible unauthorised access and the 5G outage. For the outage itself, the carrier said it had found no signs of a cyberattack — an important distinction, since the two incidents happened on the same day at the same company.
Why it matters for World Tech readers
A nationwide outage at Japan's biggest carrier is a reminder of how much everyday life now rides on a single mobile network — calls, data, payments and business systems all at once. The incident also shows why the 5G standalone distinction matters: customers on the newest network technology were the ones hit, while older 4G kept working. And the same-day online-shop suspension, whatever its cause turns out to be, will keep security watchers focused on Docomo until the company explains what happened to its servers. For readers outside Japan, the practical lesson travels well: know how to switch your phone to 4G manually, because that is exactly the workaround Docomo itself is recommending.
It is also the second major network story in Japan this week to underline how fragile flagship infrastructure can be — and it follows a run of major incidents we have covered, including the DigiCert data breach, where identity documents were exposed, and the DreamHost breach, where customer FTP passwords were stolen over two months.
Should you care?
✅ If you are in Japan on Docomo 5G SA: the service is now restored, so no workaround is needed. If you used the online shop or My docomo, watch for Docomo's notification — leaked data includes bank account numbers and identity document numbers, and Docomo plans compensation for affected people.
⏳ If you are outside Japan: no action needed — but note the pattern. The Zyxel GS1900 zero-day showed the same week how a single flaw can ripple across networks, and Docomo's outage is a reminder to keep a fallback connection ready.
FAQs
What caused the NTT Docomo outage in Japan?
Congestion in switching equipment serving 5G standalone subscribers. Docomo restored the service at around 1:20 a.m. JST on 6 November 2026 after about 14 hours of instability, and its investigation found no signs of a cyberattack behind the outage.
Which Docomo services are down?
The 5G standalone (5G SA) service was unstable — it is now restored — voice calls, data and SMS for customers on that plan. Other 5G services, 4G services and emergency calls were unaffected, according to Docomo.
How can Docomo customers get service back?
No action is needed now — the 5G standalone service was restored at around 1:20 a.m. JST on 6 November 2026. The 4G workaround was only needed while the outage lasted.
Is the Docomo outage linked to a hack?
Docomo says it found no signs the outage was caused by a cyberattack. Separately, it suspended its online shop and My docomo site over a possible unauthorised access to its servers — but the company has disclosed no connection between the two incidents.
Takeaway: NTT Docomo's 5G standalone network went unstable across Japan on 5 November 2026 — the cause was congestion in switching equipment, with no cyberattack signs — and the service is now restored. Its online shop and My docomo portal remain suspended after a separate breach that leaked personal information, including bank account numbers and identity document numbers, for up to 300,000 customers. Affected customers should watch for phishing messages and wait for Docomo's notification and compensation details.
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Sources
- Kyodo News — NTT Docomo reports nationwide 5G service disruptions
- Nippon.com (Jiji Press) — NTT Docomo Faces Network Glitches
- The Japan Times — NTT Docomo faces network glitches
- Japan Today — NTT Docomo experiencing service disruptions across Japan
- CGTN — NTT Docomo Hit by Nationwide Network Outage in Japan
- Nippon.com (Jiji Press) — NTT Docomo Chief Says Personal Info Breached in Cyberattack
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