T-12 is the document brokers and buyers most often request after the OM. It shows actual revenue (collected, not billed) and actual expenses month-by-month for the past year. Compared to pro forma — which is what the seller projects going forward — T-12 is the historical record the deal actually operated against.
A T-12 that is materially below pro forma is a negotiation lever. A T-12 that supports pro forma is a confidence signal. T-12 numbers are also what lenders use to size DSCR and debt yield, so a buyer underwriting off pro forma but borrowing off T-12 will often find their loan smaller than their cap-rate math expected.
