Cliff unlock is the vesting event when equity that was subject to a cliff period first becomes owned (or exercisable) by the holder.

How it works

Standard startup grants use time-based vesting with an initial cliff—often 12 months. If you receive 48,000 options vesting over four years with a one-year cliff, zero vests until month 12. On the cliff unlock date, 12,000 options (one quarter) vest immediately. After that, vesting usually continues monthly or quarterly for the remaining schedule. Founder shares in the cap table often mirror the same pattern via restricted stock purchase agreements. Cliff unlock is a calendar milestone, not a performance bonus—though some grants add performance cliffs. If you depart before cliff unlock, you typically forfeit the unvested grant entirely unless the board accelerates vesting in a acquisition or termination scenario.

Why it matters

• Founders: Your economic stake may look large on paper but have zero vested value until cliff unlock. Negotiate acceleration triggers and understand refresh grants for co-founders joining at different times.
• Investors: Cliffs reduce the risk of a founder walking away early with full ownership. Due diligence checks that key people are past cliff or aligned on remaining schedule.
• Employees: Job changes before cliff unlock mean leaving with nothing from that grant—a common surprise for first-time startup hires.

Common mistake

Confusing cliff unlock with the full grant vesting. Only the cliff tranche unlocks at once; the rest vests gradually afterward.

Related ideas

Cliff vesting, vesting schedule, stock options, restricted stock, and acceleration on change of control are closely related terms.