Part of our SAFE & Early-Stage Financing Guide — Open the guide →
A convertible note is a debt instrument that converts into equity at a later financing event: typically the company’s next qualified priced round: rather than being repaid in cash. It is a hybrid security used predominantly in early-stage financings (pre-seed and seed) to raise capital without requiring the founders and investors to agree on a current company valuation, deferring that negotiation to the next priced round when the company has more data points to justify a defensible valuation.
Key economic terms include: (i) principal amount (the invested capital); (ii) interest rate (typically 4–8% per annum, accruing in kind rather than paid in cash); (iii) maturity date (typically 18–36 months, at which point unconverted notes become repayable or convert at a default price); (iv) valuation cap (a ceiling on the conversion valuation: if the next round prices above the cap, noteholders convert as if the round were priced at the cap, capturing the upside); (v) discount (a percentage discount to the next-round price: typically 15–25%); and (vi) MFN (most favored nation) clause (giving noteholders the benefit of more-favorable terms granted to subsequent note investors).
The cap and discount typically operate on a “better-of” basis: at conversion, noteholders receive the more favorable of (i) the discount applied to the priced-round share price OR (ii) conversion at the valuation cap. For example, a $1M note at a $5M cap with 20% discount converting into a $10M pre-money Series A: cap conversion yields ~2x the equity that discount conversion would (because the cap is half the priced valuation), so the cap dominates. At a $6M pre-money Series A, the discount and cap produce similar results.
Convertible notes have important advantages over priced equity: speed (5–10 page note vs. 100+ page financing documents); cost ($5K–$15K legal vs. $30K–$50K for priced rounds); valuation deferral (allowing more time for traction development); and simplicity for investors and founders alike. Disadvantages include: debt classification (notes are technically debt until conversion, creating balance-sheet and bankruptcy implications); maturity pressure (founders must close a qualified round before maturity or negotiate extension); interest accrual (compounds founder dilution at conversion); and conversion-mechanic complexity in multi-note scenarios.
The U.S. market has largely shifted from convertible notes toward SAFEs (Simple Agreement for Future Equity): Y Combinator’s 2013 innovation that strips out the debt characteristics (no interest, no maturity, no repayment obligation) while preserving cap-and-discount conversion mechanics. SAFEs are simpler and founder-favorable; convertible notes remain common in jurisdictions outside the U.S., in larger rounds where investor protections matter more, and where local tax treatment favors debt over equity-like instruments. Vircon Legal advises founders on convertible note structuring: cap and discount calibration, interest and maturity term-setting, MFN scope management, conversion modeling, and the strategic choice between convertible notes, SAFEs, and priced rounds.
Newer related concepts: SAFE Post-Money.
Mechanics, conversion and the downside if no round comes
A convertible note is debt that is designed to turn into equity. Its commercial terms revolve around four levers: an interest rate (which accrues and usually converts rather than being repaid in cash), a maturity date, a discount rewarding early risk, and often a valuation cap that sets a ceiling on the conversion price. On a qualified financing the note converts into the new round’s shares at the better of the discount or cap. The critical risk founders underestimate is what happens if no priced round occurs before maturity: as a debt instrument, the note can in principle become repayable in cash, or convert at a pre-agreed fallback valuation. This is the main structural difference from a SAFE, which is not debt and carries no maturity date, and it is why maturity, repayment and extension terms deserve close attention at signing.
Frequently Asked Questions
What is a convertible note?
A convertible note is short-term debt that converts into equity at a later financing round instead of being repaid in cash.
What are the discount and valuation cap?
The discount gives note-holders a lower price than new investors; the valuation cap sets a maximum conversion valuation: both reward early risk.
How does a convertible note differ from a SAFE?
A note is debt with interest and a maturity date; a SAFE is not debt and has no interest or maturity: simpler, but a different risk profile.
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