What happens if the fielding side is too slow in the BBL?

The fielding side must be in position to bowl the first ball of the final over of the innings by 79 minutes of playing time (the cut-off time). For a reduced innings the cut-off is (innings overs minus 1) multiplied by 4 minutes, plus 2 minutes.

If the side misses the cut-off, from the start of the next over and for the rest of the innings no more than 4 fielders (instead of 5) are permitted outside the fielding restriction area. If those overs coincide with the Power Surge, a maximum of 2 fielders are permitted outside it.

The penalty does not apply if the innings is reduced to less than 10 overs (unless the penalty was already applied before the reduction), or if the innings finishes before the cut-off time.