Yes, ACH transfer payments can fail sometimes. Transaction failures can happen for a number of reasons, such as insufficient funds, bad account numbers, disabled debits from bank accounts, etc. ACH charges have the initial status of pending. It takes up to 5 business days to receive acknowledgment of their success or failure. During this time, the payment transitions to either a succeeded or failed state, depending on the client's bank. Failed ACH transfers reverse the pending balance transaction created earlier. You receive a notification in Core and the ePayment status of the associated invoice is updated in the Invoices list view. A payment entry and deposit is not created for unsuccessful transactions.