What you are actually paying
An estimated payment usually covers two things at once: income tax on your profit, and self-employment tax, which is the Social Security and Medicare contribution an employer would otherwise have split with you. Missing the second one is the most common reason a first-year freelancer's bill feels twice as large as expected.
- Income tax applies to your net profit, not your gross invoices.
- Self-employment tax covers both the employee and employer halves of Social Security and Medicare.
- Half of the self-employment tax is generally deductible against income tax, which softens the total.
