Mizuho Bank

Is Mizuho safe?

For depositors, yes. Mizuho Financial Group, one of Japan's three megabanks, had a CET1CET1 ratioA bank's highest-quality capital (mainly shares and retained profits) as a share of its risk-weighted assets. Higher means more room to absorb losses.More in the glossary capital ratio of 13.51% at 30 June 2026, more than five points above its 8.13% requirement. Yen deposits at Mizuho Bank, Ltd. are insured by the Deposit InsuranceDeposit insuranceA government-backed scheme that repays bank customers up to a set limit if their bank fails, such as the FDIC in the US or the FSCS in the UK.More in the glossary Corporation of Japan up to ¥10 million per depositor, and interest-free settlement accounts are covered in full. We score it 73/100, five points below MUFG. The gap is about reliability. In 2021 Mizuho Bank had eight system failures in seven months, and the Financial Services Agency (FSA) issued business improvement orders, the third time it had done so over IT problems at the group.

What Japan's deposit insurance covers at Mizuho

The rules are the same at every Japanese bank. Interest-bearing ordinary deposits, time deposits and similar accounts are protected up to ¥10 million of principal per depositor at each bank, plus interest. Settlement deposits, which pay no interest, can be withdrawn on demand and can be used for payments, are protected in full.

What falls outside:

• Foreign currency deposits.
• Negotiable certificates of deposit.
• Investment trusts, bonds and insurance sold at Mizuho branches, and anything held at Mizuho Securities.

Mizuho Trust & Banking is a separate bank, so deposits there have their own ¥10 million limit. Mizuho is also on the Financial Stability Board's list of global systemically important banksG-SIBA global systemically important bank: one of the large banks the Financial Stability Board lists each year because its failure could harm the world economy.More in the glossary, in bucket 1, the lowest surcharge band.

Capital and liquidity

The capital buffer is wider than MUFG's and the ratio has risen over the year. Liquidity is thinner. The coverage ratio has stayed in a 123–132% range for the past five quarters, against 140% or more at MUFG, and a large share of deposits comes from companies with balances far above the insurance limit. Such deposits can leave faster in a crisis than household savings, which is why we score liquidity a little below capital.

The system failures

Mizuho's IT record is the reason for its lower score. The trouble started at its birth. In April 2002, as the newly formed Mizuho banks opened, ATM outages, delayed transfers and duplicate debits hit customers, and the FSA ordered the group to improve its business that June. In March 2011, after the Tohoku earthquake, a surge of transfers to charity accounts overloaded nightly batch processing, causing ATM outages and delayed payments. The FSA issued orders again in May 2011.

The 2021 failures were worse. On 28 February 2021 a month-end data migration caused ATMs across Japan to stop and keep customers' cash cards and passbooks. Seven more failures followed by September. On 20 August counter services at all branches stopped for a time. On 30 September, while restoring a system, the bank ran into problems complying with asset-freezing sanctions and anti-money launderingAnti-money launderingThe rules and checks that stop criminals from moving illegal money through banks, payment firms and crypto exchanges.More in the glossary rules.

The FSA issued a first order on 22 September 2021, requiring Mizuho to review every planned system update, and a second on 26 November, requiring a business improvement plan and a report on management responsibility. A new group CEO, Masahiro Kihara, took over in February 2022. Its 2026 annual report says it still treats preventing major system failures as a priority.

For a depositor, an outage means a few hours or days without access, not lost money. That still matters if your salary and bills run through one account.

How to keep your money safe at Mizuho

1. Keep yen deposits at Mizuho Bank within ¥10 million if you want them all insured, or use an interest-free settlement account for larger sums.
2. Treat foreign currency deposits and anything bought at a branch, such as investment trusts, as uninsured.
3. Keep a second account and card at another bank so an outage does not leave you unable to pay.
4. Turn on one-time passwords for online banking and set transfer limits. Japan has no general refund scheme for scam payments you authorise yourself.

How we scored it

Capital (82) and deposit protectionDeposit insuranceA government-backed scheme that repays bank customers up to a set limit if their bank fails, such as the FDIC in the US or the FSCS in the UK.More in the glossary (84) are Mizuho's strongest factors: a buffer of more than five points over its requirement and a scheme that fully covers settlement accounts. Digital security (45) is the weakest, reflecting three rounds of FSA orders over system failures, most recently in 2021. Stability history (78) reflects public funds received in 1998 and 1999 and repaid by 2006.