Yes, you need to report self-employment income under $400 on your tax return, but you won’t be subject to the self-employment tax if your income is lower than that amount. If your total income from self-employment exceeds that amount, you will be subject to the self-employment tax. It’s important to keep track of all income you earn from side hustles throughout the year so you aren't scrambling at tax time. That includes money from survey sites and any referral rewards you may have earned. It doesn’t include cashback rewards.