Every explanation on Tax Line Hero is based on official IRS
documentation. We don't make things up, and we don't guess. Here are the
primary sources we use:
Primary sources
IRS Form Instructions — The official instructions
published alongside each form (e.g., Instructions for Form 1040).
These are the authoritative source for how to fill in each line.
IRS Publications — Detailed guidance documents like
Publication 17 (Your Federal Income Tax), Publication 525 (Taxable and
Nontaxable Income), Publication 550 (Investment Income and Expenses),
and others.
Internal Revenue Code — The actual tax law. We
reference specific code sections when explaining rules and thresholds.
IRS Tax Tips and Fact Sheets — Shorter guidance
documents the IRS publishes on specific topics.
IRS.gov — The official IRS website for forms,
publications, and current-year information.
How we write explanations
Each line explanation follows a consistent structure:
What this line means — A plain-English explanation of
the line's purpose and what number goes there.
Does this apply to you? — Quick criteria to help you
determine if the line is relevant to your situation.
Easy to overlook — Common items people miss, with
source citations.
Watch out for this — Frequent mistakes and how to
avoid them.
Every factual claim is cited with footnotes pointing to specific IRS
publications or code sections. Source badges appear throughout the
content showing which IRS document backs each point.
How we stay current
Content is reviewed and updated each tax year when the IRS publishes new
form instructions and publications. Dollar thresholds (standard
deductions, phase-outs, credit limits) are stored separately and updated
annually.
Found an error?
If you spot something that's wrong or outdated, please let us know at
[email protected]. We
take accuracy seriously.