IRS Form 1040 – Individual Income Tax Return

What Form 1040 does
Form 1040 is the primary tax return individuals use to report income, claim deductions and credits, and calculate their federal income tax liability or refund. Almost every personal tax situation, no matter how simple or complex, flows through this one core form.

Who needs to file it
Generally, anyone whose income exceeds the IRS filing threshold for their filing status and age needs to file a 1040. Filing thresholds change based on whether you’re single, married filing jointly, a dependent, self-employed, and other factors; so even people with relatively low income sometimes still need to file, especially if they’re self-employed (a much lower threshold applies) or want to claim a refund of withheld taxes.

It rarely stands alone
Form 1040 is often just the base — most real tax situations involve one or more schedules attached to it:

• Schedule 1 — additional income or adjustments (like self-employment income, unemployment, or student loan interest deduction)
• Schedule 2 — additional taxes (like self-employment tax or the Additional Medicare Tax)
• Schedule 3 — additional credits and payments
• Schedule C — profit or loss from a sole proprietorship or single-member LLC
• Schedule E — income from a K-1 (partnerships, S-Corps, trusts), rental income, or royalties

If you own a business, are a partner or shareholder receiving a K-1, or have income beyond a standard W-2, your 1040 almost certainly includes at least one of these.

Deadline
April 15 — the same date that applies if you’re filing Form 4868 for a personal extension.

How Luminary can help
We don’t just fill in a form; we make sure every schedule that actually applies to your situation is accounted for, your K-1s and business income are reported correctly, and you’re not leaving deductions or credits on the table. If your return is more complex than a single W-2, it’s worth having someone who actually looks at the full picture, not just the base form. More information can be found on our informational page, or our services page.