What is a bank statement loan?
A bank statement loan is a Non-QM mortgage that uses personal or business bank statements as the income story. The lender looks at deposits over 12 or 24 months, subtracts an expense assumption, and treats the result as qualifying income. Tax returns may be limited or not used at all.
This is not “skip underwriting.” It is a different document set, with a different credit box.
Self-employed borrowers whose tax returns understate cash flow
Owners who write off hard, cash-heavy businesses, and borrowers whose returns do not look like their accounts. The loan officer’s job is to pick the documentation path the investor will accept.
The lookback is a guideline
A 12-month program uses one year of statements: often a faster file, often a tighter credit or LTV box. A 24-month program uses two years: a smoother average, often a cleaner box. Expense factors are set by the investor and can differ between the two. Neither is “the” bank statement loan. They are two programs.
See the 12-month vs 24-month requirements comparison.
Deposit treatment is where two underwriters reach different incomes from the same statements
Each item below is a judgment call unless the guideline states it as a rule. On a desk, the underwriter decides. In an engine, the rule decides, the same way every time.
What counts. Operating deposits vs transfers, cash, and one-time spikes.
NSFs and overdrafts. Some boxes tolerate a few. Some do not.
Personal vs business accounts. Different expense factors. Different stories.
Expense factor. A percent haircut that stands in for expenses when the lender is not using a P&L.
Those calls are why the same statements can produce two incomes. Document AI can extract the lines. It does not decide whether the file fits the box. That is the AUS step. Continue with how an AUS underwrites a bank-statement file, AUS vs document AI, and the income-method comparison.