SBI Sumishin Net Bank
Japan's internet-only bank with 8M+ accounts, now majority owned by NTT DOCOMO.
On the record
Checkpoint: FSA approval and execution of rebrand to DOCOMO SMTB Net Bank plus d Account integration
The call
A profitable, well-capitalized digital bank now folded into DOCOMO, competing with other telco-linked banks for deposits rather than fighting off AI.
SBI Sumishin Net Bank is a regulated Japanese digital bank that takes deposits and offers financial services online, now fully owned by phone company NTT DOCOMO and Sumitomo Mitsui Trust after going private in September 2025. It is hard to replace because banking in Japan requires a government license and deposit insurance that only established players can get, and DOCOMO's 66 million phone customers give it built-in customers that AI or new startups cannot easily match. The biggest question is whether the planned rebrand to DOCOMO SMTB Net Bank and switch to DOCOMO's payment app (d Account) in August 2026 will go smoothly without losing customers or creating internal chaos, since it is one of Japan's largest digital banks by deposits and any misstep could hurt growth.
Why
01
AI pressure: None apparent. Banking license, deposit insurance, and DOCOMO's mobile distribution can't be replicated by a model or chatbot. Could AI do the core job? Unlikely.
02
Bigger players: Rakuten Bank and au Jibun Bank (KDDI/MUFG). Rakuten Bank already holds more deposits (~10.4T yen vs SSNB's ~8T yen); au Jibun Bank pulls in KDDI's mobile customers the same way DOCOMO now feeds SSNB. Could a giant copy it? No, they are blocked.
03
What protects it. A banking license, deposit insurance, an AA+ rating, and DOCOMO's mobile subscriber base funneling in new accounts.
What would change this call
FSA approval (or delay/denial) of the DOCOMO SMTB Net Bank trade name and license change by Aug 3, 2026. Shows whether the DOCOMO integration proceeds on schedule or faces regulatory friction.
Deposit balance and account attrition data after the d Account points integration rollout on Aug 20, 2026. Shows whether legacy SBI-linked customers stay or leave during the ownership transition.
Rakuten Bank's and au Jibun Bank's published deposit totals over the next two fiscal years versus SBI Sumishin's. Shows whether rivals are pulling ahead in the digital-bank deposit race.
Deposit balance and account attrition data after the d Account points integration rollout on Aug 20, 2026. Shows whether legacy SBI-linked customers stay or leave during the ownership transition.
Rakuten Bank's and au Jibun Bank's published deposit totals over the next two fiscal years versus SBI Sumishin's. Shows whether rivals are pulling ahead in the digital-bank deposit race.
Key numbers
- 8M+ deposit accounts, up 15% YoY
- Net income 27.7B yen, up from 23.8B yen prior year
- JCR rating upgraded to AA+ stable on 11T yen fund base
Named risks
- FSA may delay or block the Aug 3, 2026 trade name and license transition to DOCOMO SMTB Net Bank.
- Customer attrition among legacy SBI-linked users during d Account migration starting Aug 20, 2026.
- Rakuten Bank or au Jibun Bank could outpace deposit growth, eroding relative market position.
- Governance friction between DOCOMO and SuMiTB during ongoing capital reorganization.
- Bank of Japan rate shifts could compress deposit spreads across the digital-bank cohort.
Rivals, as read in July 2026
| Rival | Direction | Evidence |
|---|---|---|
| Rakuten Bank | losing to | Rakuten Bank had Yen 10.44 trillion deposits vs SSNB roughly Yen 8 trillion as of March 31, 2024 |
| au Jibun Bank | contesting | KDDI/MUFG telco-bank JV mirrors DOCOMO's new SSNB ownership structure since Oct 2025 |
| PayPay Bank | contesting | SoftBank-linked digital bank competing in same four-player telco-bank oligopoly as of 2024 |
| MUFG Bank, SMBC, Mizuho | gaining on | Megabanks hold Yen 170 to 250 trillion deposits each but cannot replicate branchless economics, per Nov 2024 analysis |
Questions people ask
- Is SBI Sumishin Net Bank still publicly traded?
- No. SBI Sumishin Net Bank delisted from the Tokyo Stock Exchange on September 25, 2025 after NTT DOCOMO's tender offer settled July 17, 2025 at Yen 4,900 per share, a 49% premium, valuing the deal near Yen 420 billion. It became a DOCOMO consolidated subsidiary on October 1, 2025.
- Who owns SBI Sumishin Net Bank now?
- As of October 1, 2025, NTT DOCOMO holds about 65.8% and Sumitomo Mitsui Trust Bank about 34.2%. SBI Holdings exited its equity stake entirely during the July 2025 tender-offer settlement. A further Yen 50 billion share transfer from DOCOMO to SuMiTB occurred December 19, 2025.
- Is SBI Sumishin Net Bank profitable?
- Yes. The bank reported non-consolidated net income of Yen 27,714 million for the fiscal year ended March 31, 2025, up from Yen 23,784 million the prior year, according to its financial results filing dated May 9, 2025.
- Could AI replace SBI Sumishin Net Bank's core business?
- No. Its banking license, deposit insurance backing, and BaaS partnerships with firms like Japan Airlines and Takashimaya are regulatory and relationship moats AI cannot replicate. The bank uses AI only for commodity tasks like its Helpippi chatbot, launched November 1, 2024, and fraud monitoring.
- Who is SBI Sumishin Net Bank's biggest competitor?
- Rakuten Bank, which held Yen 10.44 trillion in deposits as of March 31, 2024, versus SSNB's roughly Yen 8 trillion that period, per S&P Global Market Intelligence data published November 21, 2024. Other rivals include au Jibun Bank and PayPay Bank.
- Will SBI Sumishin Net Bank change its name?
- Yes, it plans to rename to DOCOMO SMTB Net Bank, Inc. effective August 3, 2026, according to a December 19, 2025 notice from Sumitomo Mitsui Trust Bank, though this remains subject to Financial Services Agency approval.
Timeline
- 2026-06-01Launched Japan's first Hybrid Mortgage Loan with partial lump-sum repayment at maturity
- 2026-01-16JCR upgraded long-term issuer rating from A/Positive to AA plus stable, citing Yen 11 trillion fund base
- 2025-12-19DOCOMO transferred approximately Yen 50 billion of shares to SuMiTB; trade name change to DOCOMO SMTB Net Bank announced
- 2025-10-01Became consolidated subsidiary of NTT DOCOMO; rebranded service brand to d NEOBANK
- 2025-09-25Delisted from Tokyo Stock Exchange
- 2025-07-17NTT DOCOMO tender offer settled at Yen 4,900 per share, roughly Yen 420 billion deal
- 2025-05-29NTT DOCOMO announced plan to take SSNB private for about 2.9 billion dollars
- 2025-04-01Announced capital and business alliance with Happiness Planet for generative AI finance agents
- 2025-01-14Announced deposit accounts exceeded 8 million
- 2024-11-01Launched generative AI customer chatbot Helpippi
Head to head
Revision history
25 July 2026
First assessed. Defensible for now. The text above is fixed as of this date and is not edited afterwards.
In the same band
Sources
- TDnet filing (2025-10-01)
- NTT Docomo to take control of online bank for $2.9B (2025-05-29)
- SMTB notice on trade name change (2025-12-19)
- SBI Sumishin Net Bank Announces Excess 8 Million Deposit Accounts (2025-01-14)
- SBI Sumishin Net Bank App Exceeded 6 Million Downloads (2025-05-21)
- Notice of Convocation, 16th AGM (2023-06-14)
- Japanese digital banks outpace megabanks in deposit growth as rates rise (2024-11-21)
- Consolidated Financial Results FYE March 31, 2025 (2025-05-09)
- JCR rating notice (2026-01-16)
- SBI Sumishin Net Bank Number of Employees 2026 (2026-06-29)
- SBI Sumishin Net Bank Releases Generative AI Chatbot 'Helpippi™' (2024-10-31)
- Capital and Business Alliance Agreement with Happiness Planet (2025-03-31)