What is tax withholding, anyway?

The 60-second version. No jargon, we promise.

STEP 1

A little form tells your employer how much tax to set aside

You
→
Form W-4
→
Your employer

When you start a job, you fill out a Form W-4. It's basically a note to your employer that says: "set aside about this much of my pay for my taxes."

You can update it whenever your situation changes. It's your form, your call.

STEP 2

Every payday, a slice of your check goes toward your taxes

YOUR PAYCHECK
Your pay$2,300
Set aside for taxes−$520
You take home$1,780
→
Your tax "bucket" fills up all year

That's all "withholding" is: pre-paying your taxes a little at a time, automatically, so you never face the whole bill at once.

STEP 3

At tax time, the bucket pays your bill

Example 1 · A perfect match (rare!)
$9,100
your total tax bill for the year
$9,100
what was set aside from your paychecks
Example 2 · How it usually goes
$12,200
your total tax bill for the year
$13,520
set aside from 26 paychecks ($520 each)
You set aside $1,320 more than you owed, so it comes back to you: refund of $1,320

That's all a refund is: your own money coming back because the bucket overfilled. When you file your return, the year's withholding is counted against your bill. Set aside more than you owed? Refund. Less? You pay the difference. Most people's numbers don't match exactly, and that's fine.

STEP 4

Now add the scholarship credit

Example 3 · The same year, with a $1,700 donation credit

The federal scholarship tax credit comes straight off your tax bill. You set aside the very same amount as before, so the bucket overfills by an extra $1,700.

$10,500
your bill, now $1,700 smaller ($12,200 less the $1,700 credit)
$13,520
the same amount set aside from your 26 paychecks
Same money set aside, but your bill is $1,700 lower, so your refund grows by exactly that much: $1,320 + $1,700 = refund of $3,020

So here's the simple part

Since that $1,700 is coming back to you anyway, you don't have to set it aside all year. Set aside about $65 less per paycheck, send that same $65 to scholarships instead, and your take-home pay stays exactly the same.

Illustration with rounded example numbers; your amounts depend on your pay and tax situation. "Set aside for taxes" here covers federal, state, Social Security, and Medicare together, to keep the idea simple. Withholding choices are always your own election on Form W-4. In plain words: this is a simplified picture, not tax advice. Please review your own numbers with your accountant or tax professional, starting with the IRS pages below.
Learn more: IRS · Tax Withholding · IRS · About Form W-4