Significant Side Income: S-Corp Tax Savings

When side income exceeds $50,000 annually, an S-corp election can save thousands in self-employment tax. This guide covers when and how to make this election.

Entity planning is the big opportunity. Once side income reaches roughly $40,000 or more in net profit, forming an S-corporation for the side business can save thousands in self-employment tax. The S-corp pays you a "reasonable salary" (subject to FICA), but remaining profits pass through as distributions not subject to the 15.3% self-employment tax. The IRS scrutinizes unreasonably low salaries, so the split must be defensible.

Separate retirement plans multiply your savings. A Solo 401(k) or SEP-IRA tied to the side business lets you shelter additional income beyond what your employer plan allows. With a Solo 401(k), you can contribute as both employee and employer, potentially deferring over $60,000 per year from the side income alone.

Home office and business deductions add up. If you use a dedicated space regularly and exclusively for the side business, the home office deduction (actual expenses or simplified method) reduces both income tax and self-employment tax.

The tradeoff: S-corp formation means payroll filings, a separate tax return (Form 1120-S), and ongoing compliance costs. The tax savings must justify the $1,500 to $3,000 per year in added accounting fees.