Promissory Note Investing: 6-12% Yields and the Traps

What Promissory Note Investing Actually Delivers

Promissory note investing sits in a productive corner of private credit: yields that can range from 6% to 12% depending on collateral and borrower quality, with structures flexible enough to serve everything from real estate bridge lending to intra-family wealth transfer. For investors already holding diversified public market exposure, the appeal is real. So are the traps.

The global private credit market has grown to over $1.5 trillion in assets under management, according to Preqin's 2024 Global Private Debt Report. That growth reflects genuine institutional demand for yield outside public bond markets. But the retail-facing end of the promissory note market is also where the SEC and state regulators consistently find some of their most active fraud cases. Understanding the difference between a well-structured private note and a fraudulent scheme requires more than enthusiasm for yield.

This article covers the mechanics, tax math, regulatory framework, due diligence process, and portfolio allocation logic that matter at the $5M+ level.

How Promissory Notes Work: Structure, Types, and Key Terms

A promissory note is a legally binding written promise by a borrower to repay a specified principal amount to a lender, on defined terms, with interest. As the investor, you are the lender. The note specifies the principal, interest rate, payment schedule, maturity date, collateral (if any), and default remedies.

The structure sounds simple. The execution details are where most investors get into trouble.

Types of Promissory Notes

Secured notes are backed by collateral, typically real estate, business assets, or equipment. First-lien real estate notes with loan-to-value ratios below 65% have historically shown loss rates below 2-3% in non-crisis periods, according to FDIC and academic research on private lending. That collateral position matters enormously in a default scenario.

Unsecured notes carry no collateral claim. They compensate with higher stated yields, but academic research on private lending consistently shows unsecured private notes have default rates in the 5-15% range for subprime or startup-stage borrowers. The yield premium rarely covers that risk adequately for most investors.

Convertible notes are common in early-stage startup financing. The note converts to equity at a future financing round, typically at a discount to the new round's price or with a valuation cap. The mechanics matter: a $500K convertible note with a $5M cap converts at a lower price per share than one with a $10M cap, meaning more dilution protection for the lender. Treat these as hybrid instruments, not fixed income.

Participating notes allow the investor to receive interest payments plus a share of profits from the underlying venture. They require careful legal drafting and a clear understanding of how profits are calculated and distributed.

Key Terms to Evaluate Before Committing

Every note should be reviewed on: interest rate and whether it is fixed or floating; payment frequency (monthly, quarterly, or balloon at maturity); prepayment provisions and any penalties; default triggers and cure periods; subordination relative to other debt; and the specific collateral description with lien priority.

The Federal Reserve's H.15 release provides benchmark rate data useful for evaluating whether a note's yield premium over comparable-duration Treasuries or investment-grade corporates actually compensates for illiquidity and credit risk.

What Returns Can Investors Expect from Promissory Note Investing?

Gross yields on private promissory notes typically range from 6% to 12% for well-secured instruments, and can reach 12-18% for unsecured or subordinated positions. Those numbers look attractive until you run the after-tax math.

The IRS taxes interest income from promissory notes as ordinary income, not at the preferential long-term capital gains rate, per IRS Publication 550. For an investor in the 37% federal bracket, a note yielding 10% gross produces an after-tax federal yield of approximately 6.3%. Add state taxes, and the picture changes further. In California or New York, where combined marginal rates can exceed 50%, that same 10% note yields roughly 5% after tax.

After-Tax Yield Comparison: Promissory Notes vs. Alternative Fixed-Income Instruments

Yields approximate as of 2024. State tax treatment varies. Consult a tax advisor for your specific situation.

The comparison with municipal bonds deserves attention. A high-grade muni yielding 4.2% tax-free is equivalent to a taxable yield of approximately 6.7% for an investor in the 37% bracket. A promissory note needs to yield meaningfully above that threshold to justify the illiquidity and credit risk. Many do not, once you account for defaults.

For strategies for high-return investing that account for after-tax yield, the math above is the starting point, not the gross rate.

SEC Regulations Governing Private Promissory Note Offerings

The SEC has issued formal investor alerts identifying fraudulent promissory note schemes as among the most common investment frauds targeting retail investors. Understanding the regulatory framework is not optional.

Promissory notes with maturities of nine months or less are generally exempt from securities registration requirements. Notes with longer maturities sold to the public typically must be registered with the SEC or qualify under a specific exemption.

SEC Regulatory Framework: Private Promissory Note Offering Exemptions

Under Regulation D Rule 506(c), the SEC requires that all purchasers of privately offered promissory notes be verified accredited investors: net worth over $1 million excluding primary residence, or annual income exceeding $200,000 ($300,000 joint). Most readers here clear that threshold comfortably.

The more relevant distinction at the $5M+ level is the qualified purchaser threshold under the Investment Company Act: $5 million in investments. Qualified purchaser status opens access to a broader universe of private credit funds and institutional-grade structured note programs with better legal infrastructure, third-party administration, and diversification than individual bilateral notes. If you qualify, that universe is worth exploring before committing capital to a single bilateral note.

State-level "blue sky" laws add another layer. Each state maintains its own securities registration requirements, and compliance varies. Cornell Law School's Legal Information Institute maintains a useful reference on blue sky law variations by jurisdiction.

For context on how structured credit instruments sit within this regulatory framework, the overlap with private credit fund structures is significant.

Are Promissory Notes a Safe Investment for High-Net-Worth Individuals?

The honest answer: it depends entirely on the collateral position, borrower quality, and how much of your portfolio is exposed.

The North American Securities Administrators Association (NASAA) consistently identifies fraudulent promissory note schemes as one of its top enforcement priorities. Cases typically involve unregistered sellers promising guaranteed returns of 10-15% or higher, pressure to invest quickly, and missing or fabricated collateral documentation.

Red Flags That Should End the Conversation

Guaranteed returns above 10-12%. No private credit instrument can legitimately guarantee returns at that level without commensurate risk. When a seller uses the word "guaranteed," that is a regulatory and factual problem.

Unregistered offerings from unverified issuers. Check the SEC's EDGAR database and your state securities regulator's database before committing any capital. An offering that cannot be verified in either system requires an explanation.

Pressure to decide quickly. Legitimate private credit deals do not evaporate in 48 hours. Artificial urgency is a sales tactic, not a market condition.

Missing audited financials. For any business-related note above $100K, you should receive reviewed or audited financial statements. Projections without historical financials are not a substitute.

Subordinated position with no collateral. An unsecured, subordinated note in a startup is effectively equity-like risk with fixed-income returns. Price it accordingly or pass.

No third-party servicing or escrow. Reputable note transactions use independent escrow agents and loan servicers. Direct payment to the issuer without third-party oversight creates unnecessary counterparty risk.

FINRA has also published guidance on private placement risks that applies directly to promissory note offerings. Their investor alert on private placements is worth reviewing before any commitment.

How Promissory Note Interest Payments Are Taxed by the IRS

The tax treatment of promissory note income is the most consistently misunderstood element of this asset class, and it is the one that most directly affects net returns for high-bracket investors.

Per IRS Publication 550, interest income from promissory notes is taxed at your ordinary income rate. In 2024, the top federal marginal rate is 37%. There is no path to long-term capital gains treatment on interest income, regardless of how long you hold the note.

Imputed Interest and the AFR Rules

If you structure a private loan, including an intra-family note, at a rate below the IRS Applicable Federal Rate (AFR), the IRS imputes interest income to you regardless of what the note actually pays. Under IRC Section 1274 and the related AFR rules, notes issued below the AFR also trigger potential gift tax consequences.

The IRS publishes monthly AFR guidance. For mid-term loans (over three years, up to nine years) in 2024, the AFR has ranged between approximately 4% and 5%. Any private note below that rate in a related-party transaction creates compliance exposure.

The Intra-Family Note Strategy

This is where promissory notes become genuinely interesting for estate planning at the $5M+ level, and it is almost never covered in generic investing content.

A parent lends $1 million to a child at the current mid-term AFR (say, 4.5%). The child invests that capital in assets returning 10% annually. The spread between the 10% return and the 4.5% AFR interest paid back to the parent (approximately $55,000 per year) passes to the next generation free of gift or estate tax. Over a decade, that spread compounds into a meaningful wealth transfer outside the taxable estate.

The mechanics require proper documentation: a formal promissory note, actual payment of interest, and ideally a term that aligns with the investment horizon. Your estate planning attorney should structure this, not a financial advisor working from a template.

For investors managing wealth across non-retirement investment accounts, the tax drag on ordinary income from notes is a meaningful portfolio construction consideration.

What Is the Minimum Accredited Investor Threshold for Private Promissory Notes?

The SEC's Regulation D sets the accredited investor floor: $1 million net worth excluding primary residence, or $200,000 in annual income ($300,000 joint) for the past two years with reasonable expectation of the same going forward.

Most private promissory note offerings are structured under Reg D and require accredited investor status. The issuer is required to take reasonable steps to verify your status, particularly under Rule 506(c).

At the $5M+ net worth level, you likely also qualify as a qualified purchaser under the Investment Company Act, which requires $5 million in investments (not net worth). That distinction matters because qualified purchasers can access Section 3(c)(7) funds, which include institutional private credit funds with more rigorous underwriting, diversification across dozens of notes, and professional servicing infrastructure. A single bilateral promissory note carries concentration risk that a private credit fund does not.

The practical implication: if you qualify as a qualified purchaser, evaluate private credit funds alongside individual notes before defaulting to a bilateral structure. The institutional infrastructure often justifies the management fees, particularly for investors who lack the bandwidth to conduct full due diligence on individual borrowers.

This connects to the broader universe of high net worth investment opportunities where qualified purchaser status opens doors that accredited investor status alone does not.

Due Diligence Framework for Promissory Note Investing

Generic advice to "do your homework" is not useful at this level. Here is a structured framework.

Borrower Analysis

Pull a full credit report and review the last three years of financial statements (audited if available). For business borrowers, calculate the debt service coverage ratio: net operating income divided by total debt service. A ratio below 1.25x on a business note should require a meaningful yield premium or additional collateral. Verify the borrower's identity, business registration, and any prior litigation or judgments through public records.

Ask directly: what is the specific use of proceeds? How will the loan be repaid? What is the exit strategy? Vague answers to these questions are disqualifying.

Collateral Evaluation

For secured notes, obtain an independent appraisal of the collateral, not a borrower-provided estimate. Run a title search to confirm lien priority. Verify that the collateral is insured and that you are named as a loss payee. For real estate collateral, confirm the LTV ratio against the appraised value, not the purchase price.

A first-lien position on real estate at 60% LTV is fundamentally different from a second-lien position at 80% LTV. Both may be described as "secured." Only one provides meaningful downside protection.

Legal Document Review

Have your attorney review the note before you sign. Specifically examine: the default definition and cure period; acceleration clauses; subordination language; any cross-default provisions; and the governing law and jurisdiction for disputes. A note governed by a jurisdiction with borrower-friendly laws may be difficult to enforce even with a valid claim.

Servicing and Escrow

Use a third-party loan servicer for any note above $50,000. The servicer collects payments, maintains records, and manages default procedures. This removes the operational burden from you and creates a documented payment history that matters if you ever need to enforce the note or sell it.

For context on how bank loan investing strategies handle servicing infrastructure at the institutional level, the parallel to individual note servicing is instructive.

How Promissory Notes Compare to Private Equity and Real Estate Debt

The comparison that matters for a $5M+ portfolio is not promissory notes versus savings accounts. It is promissory notes versus other private credit alternatives you already have access to.

Promissory Note Types: Risk, Return, and Comparison Profile

The private real estate debt fund comparison is particularly relevant. A fund investing in first-lien real estate notes across 50-100 positions offers similar yield to an individual note with dramatically lower concentration risk, professional underwriting, and quarterly liquidity. The management fee (typically 1-1.5%) is a real cost, but so is the time and legal expense of underwriting individual notes.

Private investment in public equity structures offer another comparison point for investors evaluating where private credit fits relative to equity-linked alternatives.

How Much of a $5 Million Portfolio Should Go Into Promissory Notes?

Institutional frameworks provide a defensible anchor here. Research from Cambridge Associates and the Yale Endowment model suggests that sophisticated investors typically allocate 5-15% of total portfolio value to alternative credit and private debt, with liquidity constraints as the primary limiting factor.

For a $5 million portfolio, that implies a maximum of $250,000 to $750,000 in illiquid private credit instruments, including promissory notes. Individual note positions should not exceed 1-2% of total net worth to manage concentration risk. On a $5 million portfolio, that means individual note positions capped at $50,000 to $100,000.

At $10 million or above, the math shifts slightly. The absolute dollar amounts allow for more meaningful diversification across note types, sectors, and borrowers, which is where the risk profile begins to resemble a private credit fund rather than a concentrated bilateral bet.

The allocation also depends on your existing alternative exposure. If you already hold 10% in private equity and 10% in direct real estate, adding 5% in promissory notes pushes your total illiquid alternative sleeve to 25%. That is not inherently wrong, but it requires a liquidity plan. Know your capital call schedule, your expected note maturities, and how much of your portfolio remains in liquid instruments before committing.

For peer-to-peer lending opportunities as a more liquid, lower-minimum entry point into private credit, the trade-off is lower yield and platform concentration risk rather than individual borrower concentration risk.

Maximizing returns in changing markets requires understanding how rising rates affect existing note values, particularly for fixed-rate instruments with longer maturities.

Promissory Note Investing Within a Broader Alternative Allocation

Promissory notes occupy a specific role in a well-constructed alternative sleeve: they provide fixed-income-like cash flow with a yield premium over public credit, at the cost of illiquidity and higher due diligence burden. They are not a replacement for private equity, direct real estate, or hedge fund allocations. They complement those positions by generating current income rather than deferred capital appreciation.

The practical portfolio construction question is whether individual bilateral notes are the right vehicle, or whether a private credit fund achieves the same exposure with better infrastructure. For most investors without dedicated staff to manage note portfolios, the fund structure is more efficient above $500,000 in total private credit allocation.

Below that threshold, individual notes can make sense, particularly in real estate where the collateral is tangible and the legal framework for enforcement is well-established. The intra-family note strategy discussed earlier is also a bilateral structure that no fund replicates.

What does not make sense at any allocation level: unsecured notes from unverified issuers promising double-digit guaranteed returns, bilateral deals without independent legal review, or any position sized above 2% of net worth in a single note. The fraud risk in this market is real, documented by NASAA annually, and disproportionately targets investors who move quickly on yield without completing the due diligence framework above.

The private credit market's growth to $1.5 trillion in AUM reflects genuine institutional demand. That same growth has attracted bad actors to the retail end of the market. The distinction between institutional-quality private credit and fraudulent promissory note schemes is not always obvious from the marketing materials. It becomes obvious during due diligence, which is why skipping that step is the most expensive mistake in this asset class.

References

• U.S. Securities and Exchange Commission -- "Investor Alert: Promissory Notes"
• U.S. Securities and Exchange Commission -- "Regulation D, Rules Governing the Limited Offer and Sale of Securities Without Registration Under the Securities Act of 1933"
• Internal Revenue Service -- "Publication 550: Investment Income and Expenses" (2024)
• Internal Revenue Service -- "IRC Section 1274: Determination of Issue Price in the Case of Certain Debt Instruments Issued for Property"
• Internal Revenue Service -- "Applicable Federal Rates (AFR) Monthly Guidance"
• North American Securities Administrators Association (NASAA) -- "NASAA Enforcement Report" (2023)
• Federal Reserve -- "Statistical Release H.15: Selected Interest Rates"
• Preqin -- "Global Private Debt Report" (2024)
• Cornell Law School Legal Information Institute -- "Blue Sky Laws"
• Financial Industry Regulatory Authority (FINRA) -- "Private Placements: Evaluate the Risks Before Placing Them in Your Portfolio"