A W-2 is a tax form that your employer gives you to help you fill out your federal tax return correctly. Basically, the form adds up all your wages and tips from that particular job. Every employer is required to send you a W-2 before the national tax filing deadline.

But the W-2 isn’t the whole story. If you’ve made money some other way – by working as an independent consultant, for example, or by collecting earnings on your investments, you’ll have to add up and report that income by yourself.