Deposit insurance is frequently described as a single figure per person. The actual calculation multiplies across three dimensions, which is why two households with identical balances can have very different coverage.
The limit applies per bank, not per account
Coverage is measured against the total a depositor holds at one insured institution, aggregating checking, savings and certificates together.
Opening additional accounts at the same bank therefore adds nothing, since they all count towards the same limit under the same ownership.
Splitting balances across separate insured institutions does increase coverage, because each institution carries its own limit independently.
Ownership categories multiply the available coverage
The rules recognise distinct categories such as single accounts, joint accounts, certain retirement accounts and revocable trust arrangements.
Each category receives its own limit at the same bank, so a depositor with money in several categories has coverage well above the headline figure.
Joint accounts are counted per co-owner, meaning a two-owner joint account carries a limit for each of them in that category.
Brand names are not the same as charters
Some institutions operate several consumer brands on a single bank charter, and coverage attaches to the charter rather than to the marketing name.
A depositor holding the limit at two brands that share one charter is insured once, not twice, which is easy to miss when the websites look unrelated.
Regulators publish searchable records of which brands belong to which charter, and checking takes moments compared with the exposure involved.
Pass-through coverage depends on accurate records
Funds held through a fintech app or a deposit network are usually placed at partner banks, and insurance applies at those banks rather than at the app.
Coverage passes through only if the records identify the beneficial owner of each portion of a pooled account, which places the burden on the intermediary's bookkeeping.
Failures of that reconciliation have left customers unable to access money that existed, which is an operational risk that deposit insurance does not address.
Investment products inside a bank are outside the scheme
Deposit insurance covers deposits. Mutual funds, annuities, securities and crypto assets sold through a bank are not deposits and are not covered by it.
Separate schemes protect brokerage custody against the failure of the broker, but they insure against missing assets rather than against investment losses.
Limits, categories and eligible product types are set by legislation and are revised from time to time, so the current published rules govern any particular situation.