A consultation on the proposal will begin this week and last until March, with the revised return likely to come into force later this year. The consultation will also cover ideas for submitting more returns electronically.
Andrew Hind, chief executive of the commission, said the requirement to report serious incidents would apply to all charities with incomes above £25,000.
"We want to be sure trustees are focusing on these issues," he said. "We think there are a number of cases where we learn about serious incidents a bit too late - too late to engage or block a problem because the horse has already bolted."
He said the requirement would have to be carefully framed:"We don't want to be flooded by thousands of reports, so we will have to define the level of materiality and significance.
"But we think doing this will benefit the reputation of charities generally with, for example, their beneficiaries, and that over time we will see a greater number of charities putting preventive policies in place and fewer really alarming incidents happening."