The core financial defense of a national payment network is the concept of Settlement Finality. Without strict legal boundaries, a bankruptcy court could apply the historical Zero-Hour Rule, which backdates an insolvency ruling to midnight of that day, potentially reversing a failed bank’s mid-day transactions.

[Bank Declared Insolvent at 2 PM] ---> Zero-Hour Rule Backdates Bankruptcy to Midnight ---> Reverses All Mid-day Cleared Transactions ---> Systemic Financial Gridlock

To eliminate this vulnerability, central banks enforce clear statutory safe harbors. Once an instruction passes the payment system’s designated point of finality, it is legally binding and irrevocable, shielding the transaction from court reversal and protecting the wider financial system.