You need to determine whether you can't deduct money after the balance is insufficient when you start the fixed investment business. If there is no fixed investment business, you can save money normally next month and deduct it next month. Stop deducting money unless it has not been deducted successfully for three consecutive months. This is the behavior of the fund company, which is equivalent to suspending your fixed investment plan. You need to apply for a transaction at a bank outlet again. Secondly, if additional deduction is set, the deduction will continue the next day.

In short, it's not like you said, when to save money and when to deduct it. The net value is the net value on the day of deduction.