Definition
Disallowed add-backs are the ones the buyer crosses out when they rebuild your earnings. Some are crossed out because they're not actually one-time (the "one-time" marketing campaign that happens every year). Some because they're not really discretionary (the rent on the building you own personally, charged at market rate). Some because the buyer doesn't believe the documentation. And some because the buyer just doesn't think a future owner would skip the expense — even if you do.
What it means for you
Disallowed add-backs are the ones the buyer crosses out when they rebuild your earnings — and the damage compounds beyond just the line item.
The buyer’s lens
Once a buyer thinks you've stretched on one number, they discount everything else on the page.