Tax and Bookkeeping Basics for 3D Print Sellers

This is not tax advice. It's the orientation you needed before you opened your first print shop.

Are you a business yet?

If you've sold a single print for money, the IRS considers you in business. The question isn't whether you owe — it's how much, and whether you can deduct your costs against it.

The threshold for "hobby income" vs "business income" is fuzzy, but if you're making sales repeatedly with intent to profit, you're a business. Report it on Schedule C of your 1040.

Federal income tax + self-employment tax

Two separate taxes:

• Income tax: marginal rate based on your total income. 0–37%.
• Self-employment tax: 15.3% on net earnings (Social Security 12.4% + Medicare 2.9%). This is on top of income tax.

A single filer earning $30K net from 3D printing in 2026, with no other income:

• Income tax: ~$2,000
• Self-employment tax: ~$4,200
• Total federal: ~$6,200 (20.6%)

If you also have a W-2 job pushing you into the 22% bracket, add ~22% income tax to the SE tax for an effective ~37% on print profits.

Set aside 25–30% of net profit immediately

Every dollar of profit, transfer 25–30% to a separate "tax" savings account. Don't touch it. This is the single most common failure mode for new shops — spending pre-tax money on a new printer in December and discovering you owe $5K in April.

Quarterly estimated payments

Once you owe more than $1,000 in tax, you must pay quarterly estimates or face an underpayment penalty.

Due dates: April 15, June 15, September 15, January 15.

Use IRS Direct Pay or EFTPS. Form 1040-ES has the worksheet for calculating the amount.

State income tax

42 US states have income tax. Rules vary. Your state may also require quarterly estimates. Texas, Florida, Tennessee, Nevada, Washington, Wyoming, Alaska, South Dakota, and New Hampshire have no state income tax on earned income.

Sales tax

This is the most complicated piece for online sellers.

• You owe sales tax in your home state for sales delivered there. Register for a sales tax permit when you start selling.
• Marketplace facilitator laws (Etsy, Amazon, eBay) mean those platforms collect and remit sales tax for you in most states. You still report total sales on your state return.
• Direct sales (your own Shopify, in person, via email-and-Stripe) are not covered by marketplace facilitator law. You collect.
• Economic nexus: if your direct sales into another state exceed that state's threshold (commonly $100K or 200 transactions), you have nexus there and must register and collect.

For most small shops: register in your home state, collect sales tax on direct sales there, and rely on Etsy to handle the rest. As you grow, services like TaxJar or Avalara automate multi-state compliance.

Deductions you can take

Anything ordinary and necessary for the business:

• Filament, resin, IPA, FEP, all consumables
• Printers (Section 179 lets you expense up to ~$1.16M of equipment in year 1)
• Software subscriptions
• Internet + phone (business-use portion)
• Home office (if you have a dedicated space; use the simplified $5/sqft method up to $1,500)
• Shipping costs (when paid by you)
• Etsy/PayPal/Stripe fees
• Vehicle miles to ship orders or buy supplies (67¢/mile in 2026)
• Education (Skillshare on CAD, Maker Faire admission, books)
• Professional services (tax prep, legal, accounting)

Track every receipt. Photograph it the day you spend it. Use Wave (free), Xero, or QuickBooks Self-Employed.

What you can NOT deduct

• Your time / labor (the IRS does not let you deduct unpaid owner labor)
• Personal use of the printer
• Lavish meals (50% deductible if business-purpose, fully documented)
• Capital you put into the business (that's equity, not expense)

Bookkeeping setup that takes 1 hour

1. Open a separate checking account for the business. This is the most important single step.
2. Get a debit card for that account. Run all business spending through it.
3. Connect that account to Wave Accounting (free) or QuickBooks Self-Employed.
4. Set a calendar reminder to categorize transactions weekly. 10 minutes a week beats 8 hours in April.
5. Save digital copies of receipts to a Google Drive folder by month.
6. End of each quarter, run a P&L. Calculate your estimated tax. Pay it.

When to hire a CPA

• You crossed $50K gross revenue
• You added employees or contractors
• You expanded to a second state
• You bought a printer over $5,000 (Section 179 vs depreciation choice matters)
• You're considering forming an LLC or S-Corp

A CPA costs $400–1,500/year for a small business return. They typically save more than that in deductions you'd miss.

LLC vs sole proprietor

• Sole proprietor: default. No paperwork. All income on your 1040 Schedule C.
• LLC: ~$100–800/year depending on state. Provides liability protection. Tax treatment is identical to sole proprietor by default.
• S-Corp election: only useful once you're netting $80K+/year. Can reduce self-employment tax. Adds ~$500–1,500/year in tax-prep complexity.

Start as a sole proprietor. Form an LLC when you have inventory, employees, or your first signed contract. Elect S-Corp only with a CPA's recommendation.

The annual checklist

• All revenue tracked and matched to bank deposits
• Every expense receipt categorized
• Quarterly estimates paid on time
• Sales tax filed in home state
• 1099-NECs issued to contractors paid >$600
• Inventory counted (if you carry finished goods)
• Mileage log up to date
• Schedule C ready by March 1

Do these and your shop will outlast 90% of new entrants. The ones that fail almost never fail because of bad prints — they fail because they didn't pay attention to the numbers.