My $2,400 Side Job Handed Me a $1,112 Tax Bill in April

One 1099 form, one Saturday night in April, one kitchen table with TurboTax open on the laptop and a cold cup of the coffee I made at noon and never drank. The date was April 4. The form said $4,800. The left panel of the software said federal balance due $889, and the right panel said state $223, and I added 'em twice because $1,112 did not sound like a number my side job and I had ever agreed on.

Here is what the checking account actually held that night: $1,903, with rent of $1,395 already cleared on the first, the water bill promised outta the next check, and preschool co-pay due on the tenth. That is what $1,112 was competing with. My day job pays $52,400 a year at a title company, and it turns out a second income of $4,800 rides on top of your last tax bracket, not underneath it.

Not in any software was the number that saved me. It was in a Moleskine in my cupholder, eight months of odometer readings, and in January I nearly threw it in the campus dumpster because the class was over and I was tired.

parking lot c, 9:58 p.m.

Last fall the community college up the road posted a listing for a night instructor, Business Writing 210, Tuesdays 6:30 to 9:10, 26 students, $2,400 per section. I took two sections. The schedule looked like found money: I already owned the clothes, the drive was 28 miles round trip, and I built the syllabus over one weekend in August. The catch, which nobody said out loud at orientation, was the letters in the contract: 1099, contractor, no withholding, no benefits, and no payroll office to ask.

The students kept me honest about the value in a way the contract never did. A woman named Rosa, 51, retaught herself commas at 11 p.m. after ten-hour shifts at a warehouse, and her final memo made three classmates cry, which no pricing model I have ever seen has a line for. Twenty-six enrolled that fall. Twenty-one finished. I still get emails from four of them, and one is in the bachelor's program now, and every one of those emails costs me alil of the $17.50 argument.

the moleskine in the cupholder

My dad ran a lawn business for 30 years, and his one piece of advice was write down every mile, every fill-up, every toner cartridge. Every Tuesday from September 2 I wrote the date, the odometer, and the round trip: 28 miles, lot C to my driveway. Thirty weeks of it by March, 840 miles total. His lawn ledger lived in the truck door for thirty years, and mine lived eleven weeks before it earned its keep. The IRS worksheet I printed in March put the standard mileage rate at 70 cents, which makes the drive worth $588 of tax deduction on paper, which makes my dad right about one more thing.

two hundred fourteen dollars of supplies

The supplies went on the same schedule, receipts in an envelope labeled SCHOOL. Blue books: $84. Whiteboard markers and an eraser the students kept walking off with: $27. Laser toner for printing 26 resumes at a time: $98. A ream of decent resume paper: $5. Total: $214. Every one of those counted as a tax deduction once it sat on Schedule C next to the mileage, and every one of 'em I would have bought anyways, which is the peculiar mercy of this arrangement.

the quarterly thing nobody told me

Estimated taxes are a quarterly thing, and nobody at the college mentions 'em. Not in the contract, not at orientation, not in the payroll email with the W-9 attached. The software tacked a $43 underpayment penalty onto my bill for the sin of learning this in April instead of September. Forty-three dollars. I have paid worse for modest lessons, but rarely this avoidable, and never with a W-9 sitting right there since August.

what the mileage log was worth

Run the whole thing and the side job looks like this. Gross: $4,800. Expenses: $802, which is the mileage plus the supplies. Taxable profit: $3,998. Self-employment tax: $565, both halves, employer and employee, because a contractor is somehow both at once. Federal and state on top of my day-job bracket: the rest of the $1,112. Hours: about 165 across thirty weeks, five and a half a night with prep and grading. That is $17.50 an hour after everythin', to teach adults where a comma goes in a cover letter. I have opinions about that number. I also keep going back.

i paid it on april 8

Paid the federal and the state on April 8 from checking, confirmation numbers saved as screenshots, plus $200 pulled from the vacation envelope that has held $200 since 2024. The account bottomed at $596 til payday, and I ate the pantry down instead of shopping it. My husband said the thing people say, that at least it was income worth taxing, and I handed him the Moleskine instead of answering.

the fall contract is signed

The fall contract came by email April 10, same rate, two sections again, 1099 at the bottom. I signed it April 12 with the $1,112 still clearing. The mileage log moved from the cupholder to the glovebox, 2026 edition, first entry April 14, odometer 88,211 to 88,239. That part I fixed. The rate I did not.