What is a SAFE Post-Money?
A SAFE Post-Money is the version of the Simple Agreement for Future Equity introduced by Y Combinator in 2018, replacing the original 2013 pre-money SAFE. The post-money version calculates SAFE conversion as a percentage of post-money ownership rather than pre-money, providing dilution clarity but typically increasing founder dilution compared to pre-money SAFEs at the same valuation cap.
Post-money vs Pre-money mechanics
The core mathematical difference. (1) Pre-money SAFE — valuation cap excludes converted SAFEs themselves. If USD 5M cap with USD 1M raised, SAFE holders effectively own less than 20% because the cap doesn’t account for SAFE dilution. (2) Post-money SAFE — valuation cap includes all converted SAFEs. USD 5M cap with USD 1M raised means SAFE holders own exactly 20% post-conversion (USD 1M / USD 5M). Post-money gives founders and investors clearer dilution math.
Why YC moved to post-money
Three structural drivers in 2018. (1) Dilution surprises — founders raising multiple pre-money SAFEs were surprised by cumulative dilution at conversion. (2) SAFE-on-SAFE dilution — under pre-money, each SAFE diluted prior SAFEs, creating mathematical complexity. (3) Comparability — post-money SAFEs are easier to compare to priced rounds (similar ownership math). YC published the post-money standard explicitly to address founder confusion about cumulative dilution.
Founder dilution implications
The often-misunderstood implication. Post-money SAFEs typically result in MORE founder dilution than pre-money SAFEs at the same valuation cap. Example: USD 1M raised at USD 5M cap. (1) Pre-money — SAFE holders convert at “5M pre-money + 1M raised = 6M post-money,” receiving 1/6 = 16.7%. (2) Post-money — SAFE holders convert at exactly USD 5M post-money cap, receiving 1/5 = 20%. The post-money structure shifts ~3% from founder to investor.
SAFE Post-Money variants
Three standard post-money variants from YC. (1) Valuation Cap only — converts at the cap or actual valuation, whichever is lower. (2) Discount only — converts at discount (typically 20%) to next round valuation, no cap. (3) MFN (Most Favored Nation) — converts at lowest cap/discount of any subsequent SAFE issued. Each variant balances investor protection against company flexibility.
When SAFE Post-Money is used
Standard usage scenarios. (1) YC and accelerator deals — typically use SAFE Post-Money as default. (2> Pre-seed and seed rounds — when full priced rounds are too administratively expensive. (3) Bridge financings — between priced rounds. (4) International deals — global founders increasingly default to SAFE Post-Money. The instrument has become the dominant convertible structure for early-stage financing.
Türkiye context
For Türk founders raising international capital, SAFE Post-Money is increasingly standard for pre-Series A rounds. Türk legal counsel structures SAFE-equivalent instruments in Türk-incorporated entities — typically through Turkish Code-compatible adaptations addressing TTK Article 332-339 considerations on share issuance. Türk founders should model post-money SAFE dilution carefully, as the math differs from pre-money formulas common in earlier deals.
Related: SAFE Pre-Money, Convertible Note, Valuation Cap.