SAFE vs. Convertible Note: A Chicago Startup Lawyer’s Plain-English Guide

If you’re raising money for your startup, someone will eventually ask: “Are you doing a SAFE or a convertible note?” Most founders have heard both terms. Fewer understand the meaningful differences—differences that affect your dilution, your investors’ rights, and what happens if things go sideways before your next priced round.

This guide cuts through the jargon with plain-English explanations of both instruments, a side-by-side comparison, and guidance on which is right for your Illinois startup.

What Is a SAFE?

A SAFE (Simple Agreement for Future Equity) is a contract in which an investor gives you money today in exchange for the right to receive equity in your company at a future date—typically when you close a priced funding round, get acquired, or go public.

Y Combinator created the SAFE in 2013 to simplify early-stage fundraising. A SAFE is not debt: it has no interest rate, no maturity date, and no obligation to repay principal. The investor is betting on your company’s future value.

Modern SAFEs (post-2018 Y Combinator versions) come in four flavors:

  • Valuation cap only — investor converts at a capped price, protecting them if the company’s valuation grows substantially
  • Discount only — investor converts at a percentage discount (e.g., 20%) to the price paid by investors in the next round
  • Valuation cap and discount — investor gets the better of the two
  • MFN (most favored nation) — no cap or discount, but investor gets the benefit of better terms offered to future SAFE investors

What Is a Convertible Note?

A convertible note is a loan that converts into equity under specified conditions. Unlike a SAFE, a convertible note is actual debt: it bears interest (typically 5–8% per year), has a maturity date (typically 18–24 months), and creates an obligation to repay if conversion never occurs.

Like a SAFE, convertible notes typically include a valuation cap, a discount rate, or both, giving the noteholder favorable conversion terms as compensation for investing early.

SAFE vs. Convertible Note: Side-by-Side Comparison

FeatureSAFEConvertible Note
Debt instrument?NoYes
Interest rateNoneTypically 5–8% per year
Maturity dateNoneTypically 18–24 months
Repayment obligationNoYes, if not converted
Valuation capUsually yesUsually yes
Discount rateOptionalUsually yes (10–25%)
Investor-friendlinessFounder-favorableMore investor-favorable
ComplexitySimple (2–5 pages)More complex (10–20 pages)
Balance sheet treatmentEquity (or liability)Debt
Investor negotiation leverageLowerHigher (maturity = leverage)

Which Should Your Illinois Startup Use?

The right choice depends on your stage, your investor relationships, and your fundraising leverage.

Use a SAFE if:

  • You’re pre-revenue or very early stage
  • You’re using standardized YC SAFE documents (reduces legal fees significantly)
  • Your investors are angels or early-stage funds comfortable with SAFEs
  • You want to avoid a debt obligation on your balance sheet
  • You’re doing multiple small checks from different investors (SAFEs are easy to sign and close quickly)

Use a Convertible Note if:

  • Your investors require debt treatment (some institutional investors or strategic investors prefer notes)
  • You want the interest accrual to compensate investors who are waiting longer than expected
  • You’re in a jurisdiction or industry where SAFEs have less familiarity
  • Your investors are sophisticated enough to negotiate note terms and you have leverage

The Valuation Cap: Why It Matters More Than You Think

Whether you’re using a SAFE or a convertible note, the valuation cap is the most important economic term for your dilution. Here’s why:

If your SAFE has a $5M valuation cap and your Series A closes at a $20M pre-money valuation, your SAFE investor converts at the $5M cap—meaning they receive 4x as many shares as a Series A investor paying the same dollar amount. That’s powerful dilution to the founder if the cap is low.

Most early-stage Illinois startups raise SAFE rounds at caps between $3M and $10M. Get the cap right—too low and you give away too much equity; too high and investors won’t bite.

FAQ: SAFE vs. Convertible Note

Can SAFEs expire?

Standard Y Combinator SAFEs don’t have a maturity date and don’t expire. However, some investors negotiate for a “dissolution clause” that entitles them to repayment if the company dissolves without a conversion event.

What happens if I never raise a priced round?

For SAFEs: if the company dissolves, SAFE holders typically have a liquidation preference that pays them back before common stockholders but after creditors. For convertible notes: notes become due at maturity, and investors can demand repayment or negotiate an extension.

Do I need a lawyer to issue a SAFE?

You should have a lawyer review it even if you’re using standard forms. Customizations to valuation caps, pro-rata rights, and side letters can have significant long-term impact on your cap table.

Fitter Law helps Illinois startups structure seed rounds, draft SAFE and convertible note documents, and prepare for priced rounds. View our flat-fee startup law packages.