Bank account, mandate, and signatory administration
Every entity holds bank accounts, and every account has a mandate: who signs, who instructs, who sees the statements. Mandates go stale quietly. The account that freezes after a death is usually one where the sole signatory died. This capability keeps the mandate list current, so the accounts match who is actually in charge.
Mandates kept current
The mandate is the record of who can move money on each account, and it is a governance document, not a banking detail. When someone joins the structure or leaves it, the mandate changes the same day the record changes. Every account in the structure is listed, with its signatories, and the list is checked against the banks' records, not against memory. What the banks hold and what the office holds match.
When a signatory dies
A bank account freezes because the sole signatory died. That is the first operational failure after a death, and it happens in the best-run structures if the mandate named one person. When the mandate list is current, the office knows who holds the standing to act, and the bank gets one conversation instead of a reconstruction. A structure that was administered while the owner lived can be handed over in weeks.