Build a sweep account integration that automatically moves end-of-day excess cash into a money market fund and sweeps back each morning

Steps

1. Work with your bank relationship manager to establish a sweep agreement that defines the sweep target (money market fund or interest-bearing deposit), the sweep direction (zero-balance account sweeping to a master, or a master sweeping excess above a target balance), minimum and maximum sweep thresholds, and the sweep execution time window
2. Implement an end-of-day balance collection step: call your bank's balance reporting API or retrieve a BAI2 intraday report after the day's payment activity settles to determine the available balance in the operating account before the sweep execution window
3. If your bank's sweep is fully automated (bank-side automation), configure the sweep parameters through the treasury portal rather than API calls; monitor the sweep result in the next-day prior-day statement by identifying sweep debit and credit transaction codes in the BAI2 or camt.053 file
4. For API-driven sweeps where you control the transfer, calculate the sweep amount as available balance minus your target operating balance minimum; originate an outbound ACH or book transfer to the investment vehicle account for the calculated amount, capturing the transaction reference
5. Each morning before payment runs begin, read the prior-day sweep credit transaction from the bank statement to confirm funds swept back; post matching journal entries in your general ledger: debit operating account, credit money market investment account for the overnight period
6. Model interest earned on swept funds: the money market fund will post an interest credit at period end; capture this as a separate journal entry (debit investment account, credit interest income) and reconcile it against the fund statement