I'll say this up front: I'm not your accountant. What follows is the practical, plain-language version of what most freelancers need to get right on their invoices for tax purposes. If your situation is complex — international, multi-state, S-corp — talk to a real CPA. Otherwise, keep reading.
The tax thing freelancers miss
When you're employed, taxes are withheld from your paycheck automatically. You barely notice. When you're a freelancer, nobody withholds anything. The full amount your client pays you is in your bank account — and then a chunk of it has to come back out for taxes.
Roughly speaking, in the US set aside 25-30% of every invoice for federal and state income tax plus self-employment tax. In the UK plan for 20-40% for income tax plus 9% Class 4 National Insurance. In Canada, 15-33% federal plus provincial, plus CPP contributions. These numbers are approximate — your actual rate depends on bracket and deductions — but if you don't set aside something, April will be unpleasant.
What your invoice should include (US freelancers)
If you're billing US clients as a sole prop or LLC, your invoice needs the boring basics — name, address, invoice number, line items, total — plus:
- Your taxpayer ID number. Most freelancers use their SSN. If you've got an EIN (highly recommended — costs nothing, separates business identity), use that instead. The client needs it for their 1099-NEC at year-end.
- A W-9 separately. Most clients ask for this once when you onboard. The invoice itself doesn't include it; just be ready to send it.
- Sales tax — if you actually need to charge it. Most freelance services aren't taxable in most US states. Some states tax specific services (NY taxes some IT consulting; PA taxes some creative work; HI taxes nearly everything). If you're selling physical goods or digital downloads, that's different — economic nexus laws probably apply.
What your invoice should include (UK freelancers)
- Your business name and address (your home address is fine for sole traders).
- VAT number if you're VAT-registered. You must register once turnover hits £90,000 (2026 threshold). You can voluntarily register below that.
- VAT line if applicable — standard rate 20%, with options for 5% and 0% on specific goods/services.
- Date of supply if different from invoice date.
What your invoice should include (Canadian freelancers)
- Your business name and address.
- GST/HST number if registered. Required once you exceed $30,000 in revenue over four consecutive quarters. Different provinces use different rates (GST 5% federal; HST 13–15% in HST provinces; PST/QST in BC, SK, MB, QC).
- The tax rate(s) and amount. Critical for the client to claim input tax credits.
Quarterly estimated taxes (US)
Don't skip this and don't learn about it the hard way. If you'll owe more than $1,000 at year-end, you're supposed to pay estimated taxes four times a year: April 15, June 15, September 15, January 15. Miss them and you owe a small underpayment penalty.
The IRS Form 1040-ES has the worksheet. Or — easier — divide last year's total tax bill by 4 and send that each quarter. If your income jumps, recalculate mid-year.
Deductions worth tracking
The single biggest mistake I see new freelancers make: they don't track expenses well, so they pay tax on revenue instead of profit.
What counts as a deductible business expense, broadly:
- Home office (if you use it regularly and exclusively for work)
- Software subscriptions and tools
- Computer, phone (business-use percentage)
- Internet (business-use percentage)
- Professional development — courses, books
- Travel for work, mileage if you drive
- Marketing — website hosting, ads, business cards
- Health insurance premiums (US — special rules)
- Retirement contributions (SEP-IRA, Solo 401k)
When to incorporate
For most freelancers, sole prop / sole trader is fine. You incorporate when one of these is true:
- You're consistently making over ~$80-100k/year and an S-corp could save you self-employment tax.
- You have employees or contractors and want legal separation.
- Your work has real liability exposure and the LLC shield matters.
- A client requires you to invoice through an LLC (some larger corporates do this).
Otherwise: sole prop is simpler, cheaper, and the tax math is the same for revenues under that threshold.
Three habits that save you in audits
1. Number your invoices sequentially with no gaps. Easiest way to demonstrate you're reporting everything. More on invoice numbering →
2. Keep digital receipts for every business expense. Phone photo, attached to a transaction in your bookkeeping tool. Five seconds at the moment of purchase.
3. Separate business and personal bank accounts. Co-mingling is the audit-bait that costs most freelancers. A basic free business checking account fixes it.