Convertible Notes for Startups: Terms, Conversion, and Risks

A convertible note is debt that may convert into another security under agreed conditions. It is not automatically equity, and maturity does not automatically erase the debt.

The U.S. Securities and Exchange Commission’s startup-securities guide describes a convertible note as a loan from an investor to a company that can convert into a different security, often preferred stock after a future financing or another agreed trigger.

The note, purchase agreement, company charter, later financing documents, and applicable law determine the actual result. This guide uses general U.S. startup terminology and cannot substitute for counsel reviewing a specific instrument.

How a convertible note works

A simplified sequence is:

1. An investor lends money to the company.
2. The company issues a promissory note with principal, interest, maturity, and conversion terms.
3. A defined event occurs, such as a qualified equity financing, company sale, or maturity.
4. The documents determine whether the note converts, is repaid, is extended, or gives the holder another negotiated remedy.

Conversion usually exchanges the outstanding note balance for shares under a formula. The outstanding balance may include accrued interest if the documents say interest converts.

Do not describe a note as “equity later with no repayment.” It remains a debt obligation unless and until it converts or is otherwise settled.

Core convertible-note terms

Principal

The principal is the amount lent. Confirm whether multiple closings, fees, or later advances change it.

Interest

The note may accrue simple or compound interest. The documents should state the rate, calculation method, payment timing, and whether accrued interest converts. Interest terms can also be constrained by applicable law.

Maturity date

Maturity is the date when the note becomes due under its terms if it has not already converted or been repaid. What happens then is not universal.

Possible outcomes include repayment, conversion under a maturity formula, an extension, waiver, renegotiation, or enforcement. The company may not have enough cash to repay, but inability to pay does not itself cancel the obligation.

Qualified financing

Many notes convert automatically when the company closes an equity round that meets the note’s definition of a qualified financing. The definition may include a minimum financing amount, eligible securities, and treatment of simultaneous notes.

There is no universal threshold. Read the definition in the signed note.

Valuation cap

A valuation cap is an input to the conversion-price formula; it is not necessarily the company’s current valuation and does not cap the company’s future exit value. The capitalization definition used with the cap can materially change the number of shares issued.

Discount

A discount may let the note convert at a stated reduction to the price paid by new investors. If a note includes both a cap and a discount, the documents specify how they interact—often by using the conversion price that gives the holder the better economic result, but that must not be assumed.

Conversion security

The note should identify what security the investor receives. It may be the same preferred stock sold in the new round, a separate shadow series, common stock, or another security defined in the documents. Rights can differ.

Change of control or dissolution

The note may specify repayment, a multiple, conversion, or an election if the company is sold before a qualified financing. Dissolution terms address priority when the company winds down. Available assets may be insufficient to pay all claims.

Most-favored-nation, pro rata, and information rights

Some financings add side rights or separate agreements. These are not inherent to every convertible note. Record them in the cap table and diligence materials so they do not surface unexpectedly in the next round.

A simplified conversion example

Assume, only for illustration:

• principal plus convertible accrued interest at the financing: $105,000;
• new-round share price: $2.00;
• discounted conversion price under the note: $1.60; and
• cap-based conversion price under the note’s capitalization formula: $1.25.

If the signed documents say the lower conversion price applies, the cap-based price would be used:

$105,000 ÷ $1.25 = 84,000 shares

If the discount price applied instead:

$105,000 ÷ $1.60 = 65,625 shares

This example is deliberately incomplete. Real calculations can depend on pre-money or post-money definitions, fully diluted capitalization, option-pool changes, multiple note classes, interest treatment, rounding, shadow preferred stock, and the sequence of transactions. A spreadsheet copied from another company is not a substitute for the documents.

Use the startup equity guide to review how new securities affect ownership, then have counsel and a qualified finance professional verify the closing model.

What happens at maturity?

Maturity is one of the most misunderstood terms.

Do not assume:

• the note automatically converts;
• the investor must immediately force repayment;
• the investor loses the investment;
• the company can unilaterally extend the date; or
• all noteholders have the same rights.

Start reviewing unresolved notes well before maturity. Build a schedule showing holder, principal, accrued interest, maturity, conversion triggers, consent thresholds, security, amendments, and side rights. Then discuss the available paths with counsel and noteholders.

Waiting until the company is out of cash removes options and can complicate a new financing.

Convertible note vs. SAFE vs. priced equity

The SEC’s guide distinguishes notes and SAFEs, but the label is not enough. Read the actual instrument. Tax, accounting, insolvency, securities, and corporate-law treatment can be complex.

If the company is still choosing a round structure, read what a seed round is and the angel versus VC comparison.

Benefits and tradeoffs for founders

Potential benefits

• The financing can defer a negotiated share price until a later round.
• Standardized concepts may make a small early round easier to discuss.
• Conversion can align early investors with a future equity financing.

Material tradeoffs

• Debt creates maturity and creditor considerations.
• Accrued interest can increase the converting balance.
• Caps, discounts, and multiple notes can create more dilution than a founder expects.
• Different note terms can complicate the next financing.
• A delayed priced round can bring several notes near maturity at once.
• The offer and sale of the note must comply with securities law.

“Faster” documentation is not the same as simple economics.

Benefits and tradeoffs for investors

An investor may receive a favorable conversion price and debt status before conversion, but faces substantial risks:

• the company may fail before a financing;
• assets may be insufficient at dissolution;
• the next round may not occur;
• maturity negotiations may be contentious;
• conversion terms may be diluted by definitions or later securities; and
• private securities are generally illiquid.

No cap or discount eliminates startup risk.

Founder checklist before issuing notes

1. Model conversion under the cap, discount, maturity, and sale scenarios.
2. Include all outstanding notes, SAFEs, warrants, options, and promised equity.
3. Confirm board and stockholder approvals required by governing documents and law.
4. Understand the securities-law exemption and required filings or notices.
5. Verify interest, usury, tax, accounting, and insolvency implications with qualified advisers.
6. Keep executed instruments, consents, amendments, and payment evidence organized.
7. Give investors accurate, consistent disclosures.
8. Add maturity dates and reporting commitments to a compliance calendar.
9. Do not promise future terms the company cannot control.
10. Update the cap table after each closing and amendment.

The startup due-diligence guide provides a broader data-room checklist for financing readiness.

Securities-law boundary

A convertible note is generally a security. The SEC explains that offers and sales by private companies must be registered or fit an exemption, including sales to a single investor. Filing a form or using a template does not mean the SEC approved the offering.

Engage experienced startup counsel before discussing definitive terms, circulating offering materials, accepting funds, amending a note, or calculating conversion.

This article is general educational information, not legal, tax, accounting, investment, valuation, or financing advice.