Model and track a zero-balance account (ZBA) concentration structure using Modern Treasury payment orders and ledger transactions

Steps

1. Define the ZBA structure: a master concentration account (the physical account that accumulates funds) and one or more subsidiary ZBA accounts (which return to zero each day); create corresponding Internal Accounts in Modern Treasury for each physical bank account in the structure
2. Create Ledger Accounts within a Ledger to model the economic positions: a master account ledger account and individual ZBA ledger accounts; optionally create a parent-child hierarchy in the ledger to roll up subsidiary balances to the master in reporting
3. At end-of-day, poll each ZBA account's balance via the bank reporting API or BAI2 intraday file; calculate the net amount to concentrate (positive balance) or fund (negative balance if overdraft protection is enabled)
4. Originate a Modern Treasury Payment Order (book transfer if accounts are at the same bank, ACH if at different banks) to sweep the ZBA balance to the master account; for same-bank book transfers, execution is typically same-day and does not consume a payment rail
5. Create a corresponding double-entry Ledger Transaction for each sweep: debit the ZBA ledger account and credit the master ledger account for the swept amount, with effective date set to the business date of the sweep
6. Reconcile the next-day bank statement: the ZBA account should show an opening balance near zero (the sweep may not execute to the exact penny if fees or interest posted after the sweep calculation), and the master account should show the aggregate of all ZBA sweeps as credit entries