Fundraising Instruments

Understanding SAFE Notes: How They Work and When to Use Them

Created by Y Combinator, SAFEs let founders raise faster and with fewer legal hurdles than a priced round.

Global Capital Network

Investor Relations Team

May 7, 2025
June 4, 2026
8 min read

Raising money for your startup can be complex — and in early stages, traditional priced rounds can slow you down.

That’s why SAFEs (Simple Agreements for Future Equity) have become a go-to fundraising vehicle for startups. Originally developed by Y Combinator, SAFE notes allow you to raise capital faster and with fewer legal hurdles.

But what exactly is a SAFE? How does it work? And when should you use one?

What Is a SAFE Note?

A SAFE (Simple Agreement for Future Equity) is a convertible instrument. It allows investors to give money to a startup in exchange for future equity, typically during a priced round or liquidity event.

Unlike traditional equity, SAFEs don’t set a valuation now. Instead, they convert to shares later — usually at a discount or capped valuation.

Key Components of a SAFE

Valuation Cap: The maximum company valuation at which the SAFE will convert. Protects investors from high future valuations.
Discount Rate: A percentage discount off the next priced round (e.g., 20%). Incentivizes early investment.
MFN Clause (Most Favored Nation): Allows the investor to opt into better terms from later SAFEs.
Post-Money or Pre-Money SAFE: Determines how dilution is calculated.

Example

Let’s say an investor puts in $100K on a $5M valuation cap.

Later, you raise a Series A at a $10M valuation.

Instead of paying that full $10M valuation, the SAFE investor’s money converts at the $5M cap, giving them more equity than a new investor paying full price.

Benefits of SAFEs (for Founders)

✅ Fast and simple: No legal negotiation over valuation
✅ No interest or maturity date: Unlike convertible notes
✅ Control-friendly: No board seats or investor rights
✅ Ideal for early stages: Great for friends/family, accelerators, angels

Risks and Trade-Offs

❌ Dilution surprises: Founders often miscalculate how much equity they’re giving up
❌ Stacking SAFEs: Multiple SAFEs can over-dilute founders
❌ Investor confusion: Some investors still prefer traditional equity
❌ Valuation cap signals: Too low or too high caps may spook future investors

SAFE vs. Convertible Notes

Debt Instrument? — SAFE: No. Convertible Note: Yes.
Interest? — SAFE: No. Convertible Note: Yes (typically 4–8%).
Maturity Date? — SAFE: No. Convertible Note: Yes.
Simplicity — SAFE: Easier to manage. Convertible Note: More complex.
Popularity — SAFE: Growing with startups. Convertible Note: Still common in some areas.

When to Use a SAFE

Pre-seed or seed rounds
When speed matters more than valuation
With investors who are already familiar with SAFEs
In early product development or MVP stages

When NOT to Use a SAFE

For large Series A rounds or beyond
When investor expectations are high for control or governance
If your cap table is already complex
When SAFEs would delay a priced round due to dilution concerns

How a SAFE Converts: A Worked Example

For example, suppose an investor puts $100,000 into your startup on a SAFE with a $5M valuation cap and a 20% discount. A year later you raise a priced round where new investors pay $1.50 per share, and the company has 10 million shares before the new money.

Price using the cap: $5M ÷ 10 million shares = $0.50 per share.
Price using the discount: $1.50 × (1 − 20%) = $1.20 per share.
Investor gets the better price: The SAFE converts at the lower of the two, $0.50.
Shares issued: $100,000 ÷ $0.50 = 200,000 shares — compared with roughly 66,667 shares if the same $100,000 had been invested at the round price.

Real documents define the share count used for the cap price precisely, and that definition is where pre-money and post-money SAFEs differ. Always run your actual numbers in a cap table model.

Pre-Money vs. Post-Money SAFEs in Practice

With a post-money SAFE, the cap is treated as the company’s value including all SAFE money raised. That makes the investor’s ownership easy to estimate: $100,000 on a $5M post-money cap is roughly 2% of the company before the next round. The trade-off is that each additional SAFE dilutes the founders, not earlier SAFE holders.

With a pre-money SAFE, the cap excludes the SAFE money, so ownership depends on how much is raised in total.

Stacking Multiple SAFEs

Many startups raise several SAFEs over months, often at rising caps. Using post-money SAFEs and hypothetical numbers:

$250,000 at a $5M cap ≈ 5%
$500,000 at an $8M cap ≈ 6.25%
$250,000 at a $10M cap ≈ 2.5%

Together that is roughly 13.75% of the company going to SAFE holders — before the priced round and any new option pool dilute everyone further. Add these up every time you sign a new SAFE so the total never surprises you or your next lead investor.

Deciding whether a SAFE is the right instrument at all? Our decision guide, What Is a SAFE Note and Should Your Startup Use One?, compares SAFEs with priced rounds and convertible notes.