Convertible notes let founders raise money fast without the headache of valuing a company that is too early to value. They are one of the most common instruments in early-stage fundraising, and if you plan to raise angel or seed capital, you need to understand how they work.

What Is a Convertible Note?

A convertible note is a short-term loan that is designed to convert into equity at a future financing round rather than be repaid in cash. Instead of issuing shares at the time of investment (which requires agreeing on a company valuation), the investor lends money now, and that loan converts into equity later, typically when the company closes a priced round (like a Series A). Investopedia’s overview of convertible notes covers the mechanics in depth.

The benefit for founders: you raise capital quickly without negotiating your company valuation when it is too early to know what it is worth. The benefit for investors: they get to invest early, often at a discount to the price paid by later investors.

How It Works

When a convertible note converts, the investor’s loan balance turns into equity at a price determined by the terms of the note. Two key provisions govern that price:

Valuation Cap

The valuation cap sets a maximum price at which the note converts. If the company raises its next round at a $10M valuation but the note has a $5M cap, the investor converts at the $5M price, getting roughly twice as many shares as investors paying the full $10M price. The cap protects early investors from being diluted by high valuations in later rounds.

Discount Rate

The discount rate gives the convertible note investor a percentage discount off the price per share paid by new investors in the next round. A 20% discount means if the Series A price is $1.00 per share, the note converts at $0.80 per share. This compensates investors for the additional risk of investing early.

Interest Rate and Maturity Date

Convertible notes technically accrue interest (typically 4-8% annually) and have a maturity date (usually 18-24 months). If the company has not raised a qualified financing by the maturity date, the investor can demand repayment or extend the note. In practice, most notes are extended or converted before maturity.

Convertible Notes vs. Priced Equity Rounds

In a priced equity round, investors buy shares at a fixed price per share, which requires agreeing on a pre-money valuation. This is more complex, more expensive (legal fees), and takes longer to close.

A convertible note is simpler and faster to execute. Standard documents like the YC SAFE (Simple Agreement for Future Equity) have reduced this to a two-page agreement. For early-stage rounds of $500K or less, most founders use a convertible note or SAFE rather than a priced round.

The tradeoff: with a convertible note, founders and investors are both deferring the valuation conversation. When that conversation finally happens at the priced round, it can create surprises if expectations have drifted. Those terms are typically formalized in a term sheet before the round closes.

Why It Matters for Your Business

If you are raising a pre-seed or seed round from angel investors, you will almost certainly encounter convertible notes or SAFEs. Understanding the cap and discount means you can model what dilution looks like before you sign. A $500K note with a $3M cap can look very different from a $500K note with a $6M cap when your Series A price is $8M per share.

Do not just sign the first term sheet you see. Model the conversion. Know what you are giving up. And understand how this early dilution compounds — see equity dilution for a full breakdown of how your ownership stake changes across funding rounds.

Quick Takeaway

• A convertible note is a short-term loan that converts to equity at a future financing round instead of being repaid in cash
• The valuation cap and discount rate determine how favorable the conversion terms are for the investor
• Convertible notes are faster and cheaper to execute than priced equity rounds, which is why they dominate early-stage fundraising
• SAFEs (developed by Y Combinator) are a similar, simpler instrument that has largely replaced traditional convertible notes at the pre-seed stage
• Always model the dilution before signing to understand what you are actually giving up