A marginal 1099 SBA file—one where DSCR falls just below the lender’s floor or cash flow barely supports debt service—often hinges on a single variable: whether the underwriter trusts the income number. When tax returns alone don’t paint a complete or favorable picture, a CPA letter can tip the decision. The letter doesn’t reinvent the borrower’s financials; it translates them. It explains what the numbers mean, addresses red flags the underwriter is already thinking about, and provides professional credibility that personal assurance cannot. For SBA loan brokers working with 1099 borrowers on tight margins, knowing how to position—and when to request—a CPA letter is the difference between a file that stalls and a file that closes.
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What Makes a CPA Letter Actually Work in Underwriting
An underwriter reviews a 1099 borrower’s income through three lenses: tax return consistency, bank deposit corroboration, and narrative credibility. A CPA letter doesn’t change the tax returns. It does two things that matter: it signals that a licensed professional has examined the file and stands behind the income figure, and it provides a written explanation of anomalies that would otherwise sit unanswered in the underwriter’s mind.
The SBA does not mandate CPA letters, and no regulatory body requires one. What the U.S. Small Business Administration does require is that the borrower’s income be verifiable and reasonably supported by documentation. A CPA letter is a voluntary tool that fulfills that requirement more persuasively than a blank stare at confusing Schedule C entries.
The best CPA letters address a specific weak point. Say the borrower’s 2024 Schedule C shows net income of $185,000, but 2023 showed $165,000 and 2022 showed $142,000. An underwriter scanning those numbers might flag the volatility as a risk factor. A two-paragraph CPA letter explaining that the borrower added a major client in Q3 2024, supported by a client contract in the file, turns “unexplained jump” into “documented business growth.” The letter doesn’t claim the income is stable—it explains why the growth occurred and anchors it to external evidence.
The Anatomy of a CPA Letter That Passes Underwriting Scrutiny
Underwriters develop a feel for CPA letters that carry weight versus those that don’t. A strong letter has these elements:
- Letterhead and direct contact. The CPA’s actual office letterhead, not a template, with a phone number the underwriter can call. An email address is good; a callback line is better.
- Specific income figure and tax year. “I have reviewed the 2024 Schedule C for [Borrower Name] and confirm net self-employment income of $185,400 as reported on the filed return” is credible. “The borrower’s income is stable” is not.
- Clear statement of work performed. “I prepared [or reviewed] the 2024 tax return” or “I have been the borrower’s accountant for three years.” Vague language—”I am familiar with the borrower’s financial situation”—weakens the letter’s authority.
- Specific explanation of anomalies. If deductions jumped, revenue dipped, or a year-over-year number changed meaningfully, say why. Cite a contract, a lease, a hiring date, or a business event. Do not leave the underwriter guessing.
- Forward-looking narrative (when warranted). If the letter can address whether the income level is likely to sustain, do so—but only if the CPA has a factual basis (new contract in place, expanded team, recurring revenue agreements). Speculation weakens the letter.
A Worked Example: When the Letter Closes the Deal
Imagine a consultant—let’s call them borrower S—who earned $195,000 net on their 2024 Schedule C. The DSCR pencils at 1.19x based on that income; the lender’s floor is 1.25x. The file is $30,000 of DSCR short.
Underwriting digs into the income and finds that 2023 was $168,000—a 16% jump in one year. Bank deposits show sporadic deposits from three major clients, each varying month to month. The P&L shows a spike in contract labor (Schedule C line 26) that matches the revenue increase. The underwriter’s summary reads: “Income appears supported but volatility and year-over-year growth are steep. Unclear if 2024 level is sustainable.”
A CPA letter from borrower S’s accountant states: “I have prepared [borrower S]’s tax returns for four years. The 2024 income increase reflects two new enterprise clients retained in Q2 and Q4, both under signed three-year service agreements [copies enclosed]. I have reviewed the signed contracts and confirm annual revenue of approximately $198,000 from these engagements. The borrower’s core client base remains stable at $127,000 annually. The new contracts carry a 95% renewal rate in their category and include automatic renewal clauses. Based on the contractual commitments and the borrower’s four-year track record of client retention, the 2024 income level is reasonably expected to sustain through 2025 and beyond.”
That letter is not inflating the income. It is explaining what the underwriter is already thinking: whether $195,000 is a fluke or a legitimate business expansion. The signed contracts in the file verify the CPA’s claim. The letter pivots the narrative from “suspicious spike” to “documented growth with contracted revenue.” The DSCR does not change, but the underwriter’s confidence in that DSCR increases. In marginal files, confidence is sometimes the only variable that moves.
When a CPA Letter Doesn’t Help (and When to Know the Difference)
A CPA letter cannot fix an unfixable file. If the borrower’s income is genuinely below the lender’s minimum threshold and there is no new information to layer in—no hidden contract, no recurring revenue that was missed, no clear explanation of a dip—the letter will not manufacture approval. A weak or boilerplate letter can actually hurt the file by signaling that the CPA could not find enough substance to speak credibly about.
A letter that says “I confirm the borrower earned $185,000 in 2024 and anticipate similar earnings in 2025” does not move the needle if the underwriter is already skeptical of sustainability. The letter needs to answer the underwriter’s unspoken question: “Why should I believe this income will persist?” If the answer is “I don’t know,” the letter should not be submitted.
The best time to request a CPA letter is when a specific question arises during underwriting—not preemptively for every 1099 file. If the file is clean, the income is stable, and the borrower meets the DSCR floor, a CPA letter adds bulk without substance. If the file has a concrete issue that a CPA can explain (a one-time deduction that reduced net income, a business expansion that caused a revenue jump, a shift in client composition), the letter is worth the time and cost.
Positioning the CPA Letter in the File
The letter should be addressed to the lender, not to the borrower, and should be submitted as part of the official loan file—not as an email attachment to the underwriter. It belongs in the same section as the tax returns and the personal financial statement, with a clear document label: “CPA Letter – [Borrower Name] – [Tax Year].” If multiple years are discussed, date the letter clearly and ensure the CPA references each year addressed in the letter itself.
The broker’s role is to suggest the letter to the borrower when it is warranted, then brief the borrower’s CPA on what the underwriter is actually questioning. A CPA who understands the specific concern can write a targeted, persuasive letter in 15 minutes. A CPA who is asked to “write something to help the loan” may produce a generic, unhelpful letter that wastes everyone’s time.
The Math: How a CPA Letter Affects DSCR Validation
DSCR itself does not change when a CPA letter is added. DSCR is calculated from the borrower’s stated income and the loan’s projected debt service. A $195,000 income still produces the same DSCR regardless of how many letters support it. What changes is the underwriter’s confidence that the $195,000 figure is accurate and sustainable.
In marginal files, confidence is a form of risk adjustment. An underwriter who doubts income will often reduce it by 10–20% internally, which tanks DSCR further. A CPA letter that resolves that doubt prevents the invisible haircut. The borrower never sees the adjustment that was almost made, so the benefit is often invisible in the final approval—but it is the reason the file cleared when it might otherwise have been declined.
Drafting the Request: What to Tell the Borrower’s CPA
When you advise a borrower to get a CPA letter, be specific about what the underwriter needs to hear. Instead of “the lender wants a letter,” say something like: “The underwriter flagged that your revenue increased 16% from 2023 to 2024. He wants to understand if that’s a one-time bump or if you’ve landed permanent new clients. Your CPA should reference the signed contracts you mentioned and confirm that the new revenue is contractually committed for at least the next 12 months.”
That level of detail helps the CPA write a letter that actually addresses the risk, rather than a generic attestation that does nothing.
Frequently Asked Questions
Does a CPA letter replace the need for filed tax returns?
No. The CPA letter supports and explains the filed tax returns; it does not replace them. Underwriters will always require a CPA-prepared or self-prepared tax return for at least two years, along with supporting bank statements and deposits. The letter is an add-on that clarifies ambiguities or validates numbers that are difficult to understand from the return alone.
What if the borrower’s CPA says they can’t write the letter because they didn’t prepare the return?
A CPA does not need to have prepared the return to write a credible letter. They can review the filed return and the supporting records (bank statements, invoices, contracts) and attest to the income based on that review. The letter should state what work the CPA performed—”I reviewed the 2024 Schedule C and supporting bank statements”—so the underwriter knows the basis for the CPA’s opinion. A return-preparer CPA carries more authority, but a reviewing CPA is better than no CPA at all.
How much does a CPA letter typically cost the borrower?
Cost varies by region and CPA firm, but most CPAs charge $300–$800 for a focused CPA letter. Some charge a flat fee; others bill it as billable time at their standard rate. This should not be a decision blocker. In a marginal file where a $200 letter is the difference between approval and decline, the math is clear. That said, the letter should only be requested when there is a genuine issue to address—not as a routine add-on to every 1099 file.
Can the borrower write their own explanation letter instead of asking the CPA?
A borrower explanation letter is not the same as a CPA letter and will not carry the same weight with underwriters. An underwriter may ask for a borrower statement to understand the borrower’s own perspective, but a CPA letter carries the credential and liability of a licensed professional. Underwriters trust licensed credentials; they trust borrower self-interest less. If the issue requires professional credibility to resolve, a CPA letter is the right tool.
What if the underwriter still declines the file after the CPA letter is submitted?
A CPA letter can strengthen a marginal file, but it cannot override an underwriter’s decision if the core metrics do not support approval. If DSCR is 1.15x and the lender’s floor is 1.25x, even the best CPA letter won’t move the needle. A stronger file would require either a lower loan amount, a higher income figure from the borrower’s own records, or a co-borrower or co-signer. The letter is a risk-reduction tool for files that are close, not a fix for fundamentally weak metrics.
The takeaway for brokers: A CPA letter is an underutilized tool that works best when deployed strategically. It doesn’t change the numbers, but it changes the story around them. In a marginal 1099 file where DSCR is tight and income volatility is an open question, a targeted CPA letter from a borrower’s trusted accountant can be the margin of approval. Use it when a specific, addressable issue exists—not as a routine add-on. And when you do use it, be direct with the borrower’s CPA about what the underwriter is questioning, so the letter speaks to that specific concern rather than offering generic reassurance.
This article is educational and does not constitute lending advice — confirm current SBA program requirements with your lender before submitting a file.
This article is educational and does not constitute lending advice — confirm current SBA program requirements with your lender before submitting a file.
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