If founders stock is issued subject to a vesting period, each founder should make a Section 83(b) election with the IRS within 30 days of purchasing the restricted stock. If a founder fails to make a 83(b) election, each vesting milestone will be a taxable event for the founder. “Income” will be calculated as the difference between the FMV of the portion of stock that vested and the original purchase price of the newly-vested portion.
Thus, failure to make an 83(b) election could leave the founder with a tax bill without experiencing a liquidity event.
The 83(b) election neutralizes this potential disastrous tax consequence, and the founder recognizes “income” upon the initial restricted stock purchase. This income is usually $0, as the initial restricted stock purchase price is usually made at FMV.