A deduction lowers the amount of income you get taxed on. A credit lowers the tax itself, after it's been figured. That's why a credit is generally worth more per dollar than a deduction of the same size — it's coming off the bill rather than off the base the bill is calculated from.
Two Different Places in the Calculation
Tax is figured from income. A deduction acts earlier, shrinking the income that gets run through the calculation. A credit acts later, reducing the result.
Same direction, different leverage. People use the words interchangeably and they are not interchangeable.
Not All Credits Behave the Same
Some credits can only reduce what you owe to nothing. Others can go further and produce a refund beyond what you paid in. That distinction makes a real difference to who benefits from them.
Which credits exist and who qualifies changes regularly, which is exactly why this page doesn't list any.
Why This Belongs With Your CPA
Knowing the difference helps you ask better questions. It doesn't tell you what you qualify for, and most of the value is in knowing what applies to your situation.
For anybody with a business, a ranch or several income sources, this is firmly CPA territory, and the planning is worth more than the filing.
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