A cut off period is like a deadline for things to be done. Think of it like the time you have to finish a puzzle before you go to bed. Once the cut off period for the puzzle is reached, you have to stop working on it and go to bed.
In some situations, businesses or organizations may have cut off periods for things like submitting paperwork or making payments. This means that if you don't turn in your paperwork or make your payment by that cut off period, you'll have to wait until the next cut off period to do it.
This helps everyone stay organized and know when things need to be done. It's like a schedule that helps everyone stay on track so that things can run smoothly.