Is It Smart to Rely on Bank Statements for Underwriting?
Bank statements are one of the most requested documents in lending, and for good reason. But using them as a primary source of truth leads to inaccurate repayment capacity figures, inefficient underwriting, and missed T.A. opportunities.
The allure of bank statements
Financial literacy can be a major barrier to CDFI borrowers. Often equipped with only limited education in bookkeeping, the mere mention of a P&L Statement or Balance sheet can lead to sweaty palms for many business owners. And as mission-driven lenders, we need to be meeting clients where they’re at, not asking them to jump to a bar they can’t reach.
Bank statements appear to offer a simple solution. They are highly detailed and readily accessible with just a couple clicks—so what’s not to love?
The quiet danger of underwriting with bank statements
Despite the upsides, formally trained underwriters avoid using bank statements as primary sources—documents that stand on their own in verifying a borrower’s finances.
We don’t use bank statements as primary sources because of what they can’t tell us:
What type of transaction is this?
Operating expenses or capital expenditures? Revenue or loan proceeds?How frequent is this transaction?
Was that expense for an annual fee, or a monthly one?Who was the transaction for?
Was it business or personal?Who earned income and for what?
Is a payroll deposit someone’s salary or their spouse’s? Does it include overtime, a bonus, or commission?
Without this information, we can’t hope to get an accurate picture of a borrower’s finances. Think of it like this. A bank statement only really answers the question: “Did the borrower’s account balance go up or down?” The question we actually need to answer is: “Does this business generate enough cash from revenue to cover its operating costs and the new debt payment?” This distinction is the difference between bank capacity and operating cash flow:
Bank Capacity
Measures: net change in account balance
Formula: total cash in minus total cash out
Includes everything: loans, transfers, equipment purchases, owner compensation
Operating Cash Flow
Measures: business performance from core operations
Formula: revenue received minus operating expenses
Excludes: financing, investing, owner transactions, transfers
While a bank statement can give you bank capacity, we need financial statements like a Balance Sheet, P&L Statement, and Statement of Cash Flows to determine operating cash flow. These documents separate financing, investing, and owner transactions from operating transactions—isolating the information underwriters actually need from all the noise we don’t.
Let’s look at a couple of examples.
When bank capacity can be misleading
Scenario 1
Loan proceeds look like revenue
A business receives a $200K merchant cash advance while struggling with operations.
Bank Capacity shows a strong cash surplus (+$180K), making the business look healthy
Operating Cash Flow shows an actual operational loss (-$20K)
⚠ Bank Capacity makes over-leveraged businesses appear creditworthy.
Scenario 2
Capital expenditures distort the picture
A profitable restaurant spends $40K renovating its kitchen to increase capacity.
Bank Capacity is negative (-$15K), making the business look like it’s operating at a loss
Operating Cash Flow demonstrates core profitability (+$25K) by excluding the capital expenditure
⚠ Bank Capacity penalizes businesses that invest in growth.
These are just two examples of the many ways that bank capacity can fail to capture an accurate picture of a business’s finances. The bottom line is, if you rely on bank statements alone, your numbers will usually be wrong.
The efficiency myth
Lenders often push back when we discourage them from using bank statements as primary sources. They say they can calculate Operating Cash Flow by walking through an applicant's bank statements together, live. The instinct is a generous one. Nobody wants to ask a business owner for documents they don't have or can't easily create.
Unfortunately, this shortcut doesn’t deliver the efficiency win that we might wish for. Combing through bank statements one transaction at a time is a taxing process for both lenders and clients. Any speed gained by skipping documentation is lost in the endless back and forth.
The better path is usually a clear, finite request. Tell the applicant exactly what you need, and then offer to help them produce it. That might be a simple template, a short working session, or a walkthrough of how to pull the numbers from their own records. It should not be a series of phone calls spent parsing transactions line by line. The goal is to build the P&L with the client, not for them.
Good intentions, hidden costs
There’s an additional risk that’s perhaps even more noteworthy than inaccurate numbers and a loss of efficiency. If a Loan Officer builds a client’s P&L Statement for them using bank statements, the client walks away from the process without the one thing that would actually serve them long term: an understanding of how to track their own numbers. You’re missing a valuable technical assistance (T.A.) opportunity.
When bookkeeping never happens because the lender is doing the work instead, the business owner doesn't build the skill. Helping a client get set up with basic bookkeeping does something bank statement underwriting never will: it gives the business owner tools to actually run and understand their business. It prevents them from missing a cash flow issue until it’s too late to fix. And the next time they need capital, they’ll be starting from a much stronger place.
It’s not all bad news
When you use bank statements in place of financial statements, you get the worst of all worlds—unreliable repayment capacity calculations, inefficient use of organizational resources, and missed opportunities for essential technical assistance.
But that doesn’t mean you shouldn’t collect or review them! Underwriters use bank statements for many things, and in some instances, they can provide unique insight that other documents cannot.
CDFI lenders use bank statements to look for the following things at underwriting:
Income sources that have recently stopped or been reduced
Overdrafts, non-sufficient funds (NSF) fees, and negative balances
Undisclosed debt that needs to be added to repayment capacity calculations
Undisclosed income sources that can be added to cash flow
Signs of fraud or tampering
The final thing that bank statements are really good for? Corroborating internal financial statements. If you have a P&L Statement that shows $10,000 a month in average business revenue, do bank statements show deposits around that level? If not, we need to understand why.
Bank statements are wonderful tools, but we need to be careful about asking them to do more than they were designed for. The wrong tool costs you accuracy and efficiency. It also costs your client a skill. Our advice? Teach them to track their own numbers instead. Your process will be faster, your numbers more accurate, and your clients' businesses stronger.