There is also the case that a letter notifies any carers and those children/siblings etc who have power of attorney to keep track of what was going into any person's account.
When my wife's stepmother died a few years ago, the letter of notification arrived re. her heating and her executor, who hadn't even though about it, was able to notify the relevant authorities that the bank account was now closed and no longer applicable.
Our allowances, joint £200, are due any time. Our car went wrong on Wednesday of this week and cost £234.
Oh well.