I set up my 積立NISA at the start of this year and thought all was peachy. I maxed out the contributions through monthly payments, and 2 bonus payments a year.
I double checked when I get my bonuses, and selected those months for extra money to be added, however, I now realise the error I fell into. I selected the month when the purchases would be made, not the months when the extra money should be withdrawn. Knowing I get my bonus in June and December, I selected June and December in the bonus payment system, however, this means that the money will be withdrawn in May and November respectively (as the money is withdrawn at the end of the previous month).
Unfortunately, all changes to 積立NISA need to be done by the 11th of the same month, so I can't fix this upcoming withdrawal. Luckily I have enough cash to cover it, but I've made sure to fix it for my winter bonus.
This is with Rakuten, so I don't know what the setup is like with other brokerages.