SAFE Starter Kit: Everything Founders Need to Know

The Simple Agreement for Future Equity (SAFE) has become the standard for early-stage startup fundraising. This guide explains how SAFEs work, when to use them, and how to track them properly.

What is a SAFE?

A SAFE (Simple Agreement for Future Equity) is a financing contract where an investor gives you money now in exchange for the right to receive equity later, typically when you raise a priced round.

Created by: Y Combinator in 2013 Purpose: Simplify early-stage investment without the complexity of convertible notes

SAFE vs. Traditional Equity Round

Aspect	SAFE	Priced Round
Legal cost	$0-500	$15,000-50,000
Time to close	Days	Weeks to months
Valuation set?	No (usually)	Yes
Board seat	No	Often
Complexity	Very simple	Complex

Types of SAFEs

Pre-Money vs Post-Money SAFEs

Post-Money SAFE (Recommended)

• The valuation cap is the company's value AFTER the SAFE converts
• Easier to calculate how much the investor will own
• Current Y Combinator standard

Pre-Money SAFE (Legacy)

• The valuation cap is the company's value BEFORE the SAFE converts
• More complex ownership calculations
• Used less frequently today

Example:

• You raise $500K on a $5M post-money SAFE
• Investor will own exactly 10% ($500K ÷ $5M) at conversion
• Simple math, clear expectations

Valuation Cap vs Discount

Valuation Cap: Maximum valuation at which the SAFE converts

Discount: Percentage discount from the priced round valuation

Most Favored Nation (MFN): If you offer better terms to a later investor, earlier investors get those terms too

Common terms:

• Cap only: $5M-15M for pre-seed, $10M-25M for seed
• Discount only: 15-25% discount
• Cap + Discount: Investor gets the better of the two

How SAFE Conversion Works

Trigger Event

SAFEs convert to equity when one of these happens:

1. Equity Financing — You raise a priced round (Series A/Seed)
2. Liquidity Event — Company is acquired or goes public
3. Dissolution — Company shuts down (investor gets money back first)

Conversion Example

Scenario:

• SAFE: $100K at $4M post-money cap
• Series A: $3M raised at $12M pre-money valuation

Calculation:

1. Series A price per share: $12M ÷ 10M shares = $1.20/share
2. SAFE conversion price: $4M ÷ 10M shares = $0.40/share (uses cap, not Series A price)
3. SAFE investor shares: $100K ÷ $0.40 = 250,000 shares
4. Regular Series A investor shares: $3M ÷ $1.20 = 2.5M shares

The SAFE investor gets 3x more shares per dollar because of the cap.

SAFE Terms to Understand

Pro Rata Rights

Allows investors to maintain their ownership percentage in future rounds by investing more.

Standard: Investors with SAFEs over $100K get pro rata rights

Side Letters

Additional agreements that modify SAFE terms, such as:

• Information rights (financial updates)
• Board observer rights
• Pro rata in future rounds

Pre-Money vs Post-Money SAFEs: Detailed Comparison

Pre-Money SAFE Ownership Calculation

With pre-money SAFEs, multiple SAFE investors dilute each other at conversion.

Example with two pre-money SAFEs:

• SAFE 1: $200K at $4M cap
• SAFE 2: $300K at $5M cap
• Series A: $2M at $10M pre-money

The ownership calculation becomes circular and complex.

Post-Money SAFE Ownership Calculation

With post-money SAFEs, each investor's ownership is clear and independent.

Same example with post-money SAFEs:

• SAFE 1 ($200K at $4M): Owns 5%
• SAFE 2 ($300K at $5M): Owns 6%
• Total SAFE ownership: 11%

Much simpler math!

SparkLaunch Feature: Our SAFE Tracker automatically calculates ownership percentages for both pre-money and post-money SAFEs, and shows the fully diluted cap table.

SAFE vs Convertible Note

Key Differences

Feature	SAFE	Convertible Note
Maturity date	None	Yes (1-2 years)
Interest	None	Yes (2-8%)
Debt/Equity	Equity	Debt
Default risk	None	Yes
Complexity	Simple	More complex

When to Use Each

Use a SAFE when:

• Raising from angels or VCs who accept SAFEs
• You want the simplest possible structure
• You want to avoid interest accrual

Use a Convertible Note when:

• Investor requires it (some family offices prefer notes)
• You're in a state with SAFE legal uncertainty
• Investor wants interest as additional return

How to Raise Money with SAFEs

Step 1: Determine Your Terms

Decide on:

• Amount: How much are you raising?
• Cap: What valuation cap makes sense?
• Type: Post-money (recommended) or pre-money?
• Pro rata: Will you offer it?

Step 2: Use Standard Documents

Download the standard YC SAFE documents:

• Post-Money SAFE (valuation cap)
• Post-Money SAFE (discount)
• Post-Money SAFE (MFN)

Do not try to create custom SAFE documents without a lawyer.

Step 3: Track Every SAFE

For each SAFE, record:

• Investor name and contact
• Investment amount
• Valuation cap
• Date signed
• Any side letters

SparkLaunch Feature: Track up to 1 SAFE on our free plan, 3 on Startup, and unlimited on Growth. The cap table automatically updates when you add SAFEs.

Step 4: Communicate with Investors

Keep SAFE investors updated on:

• Major milestones
• Hiring announcements
• Product launches
• When you start raising the next round

SAFE Tracking Best Practices

Maintain a SAFE Register

Create a table tracking:

Investor	Date	Amount	Cap	Type	Converted?
Angel 1	1/15/26	$50K	$5M	Post	No
VC Fund	2/1/26	$200K	$8M	Post	No

Model Conversion Scenarios

Before raising a priced round, model how SAFEs will convert:

• What cap table will look like post-conversion?
• How much dilution will founders face?
• Is there room for new investor ownership targets?

SparkLaunch Feature: Our Dilution Scenarios tool lets you model different fundraising scenarios and see exactly how SAFEs will convert.

Common SAFE Mistakes

1. Using pre-money when you mean post-money — Confirm with investors which type you're using
2. Not tracking side letters — These modify SAFE terms and must be tracked
3. Stacking too many SAFEs — Too much SAFE financing can kill your Series A
4. Ignoring pro rata obligations — Budget for existing investor participation
5. Not modeling conversion — Understand your cap table before your Series A

SAFE Resources

• Y Combinator SAFE documents: ycombinator.com/documents
• SparkLaunch SAFE Tracker: Built into your cap table
• SAFE Calculator: Coming soon to SparkLaunch

Checklist Before Signing a SAFE

• Confirm post-money vs pre-money
• Agree on valuation cap
• Discuss pro rata rights
• Review for any side letters
• Add to your cap table immediately
• Send investor a copy of signed SAFE
• Update your SAFE tracking spreadsheet