The complete 1099 contractor invoicing guide for 2026

What makes a 1099 contractor different from an employee?

A 1099 contractor — officially classified as an independent contractor — is a self-employed worker who provides services to clients without being on their payroll. Instead of a W-2 form at year-end, you receive a Form 1099-NEC from each client who paid you $600 or more during the calendar year.

Key differences from W-2 employment:

• You pay your own taxes, including self-employment tax (15.3% on top of regular income tax)
• No employer withholds taxes from your payments — you make quarterly estimated tax payments directly to the IRS
• You can deduct legitimate business expenses (home office, equipment, software, professional development)
• You invoice for your services rather than receiving a paycheck

Before you send your first invoice: the W-9

Before invoicing any new client, send them a completed W-9 form. The W-9 provides your legal name, address, and either your Social Security Number or EIN (Employer Identification Number). Clients need this information to file your 1099-NEC at year-end.

Always send a W-9 before your first invoice — not after. Some clients won't process payment without one on file, and chasing it later slows everything down.

You can download the current W-9 form free from irs.gov. Fill it out, sign it, and email it to your client's accounts payable contact before any billable work begins.

SSN vs EIN — which should you use?

If you don't have an EIN, you'd use your SSN on the W-9. However, getting a free EIN from the IRS is strongly recommended — it takes about 10 minutes online at irs.gov and protects your identity. Once you have an EIN, use it in place of your SSN on all business documents. It looks more professional and keeps your personal identity separate from your business dealings.

What to include on a 1099 contractor invoice

Every contractor invoice should include the following. Missing any of these can delay payment or cause issues at tax time:

• Your full legal name (or business name if you have an LLC)
• Your mailing address
• Your email address and phone number
• Your EIN or SSN (optional on invoices — it's on the W-9)
• Client's full legal business name and billing address
• A unique invoice number
• Invoice date and payment due date
• An itemized description of services rendered
• Quantity, rate, and line item total for each service
• Grand total due
• Payment method details (bank info or Stripe/PayPal link)
• Your payment terms (Net 15, Net 30, Due on Receipt)

Payment terms for contractors

Which terms should you use?

Net 30 is the most common US business payment term, but as an independent contractor, shorter terms work in your favor. Consider:

• Due on Receipt — for final deliverables, project completions, or one-time invoices
• Net 15 — for ongoing work with newer clients
• Net 30 — for established clients with a solid payment track record

Never extend Net 60 or Net 90 terms as a solo contractor — those are enterprise payment schedules and will destroy your cash flow.

Deposits and milestone billing

For projects over $1,000, requiring a 25-50% deposit before starting work is professional and expected. You can structure longer projects with milestone invoices — 25% upfront, 50% at midpoint, 25% on final delivery. This protects you if the engagement ends early and keeps your cash flow steady throughout the project.

Taxes and invoicing — what you need to track

As a 1099 contractor, your invoices are your primary income record. Here's what to keep in order:

• Keep copies of every invoice you send — these are your proof of income
• Track payment dates — you need to know when you were actually paid, not just when you invoiced
• Make quarterly estimated tax payments — typically due in April, June, September, and January
• Reconcile your 1099-NECs in February — clients must send them by January 31st. Cross-reference against your own invoice records to catch any discrepancies

A good rule: set aside 25-30% of every payment you receive into a separate savings account designated for taxes. It removes the sting of quarterly payments.

Do 1099 contractors charge sales tax?

In most US states, services are not subject to sales tax — so most contractors (consultants, designers, developers, writers) do not need to charge sales tax. However, some states tax certain services, and if you sell digital products or software, different rules may apply.

When in doubt, consult a CPA who works with independent contractors in your state. The IRS and most state tax authorities have published guidance on taxable vs. non-taxable services. This is one area where a one-time consultation with a professional saves you significant headache later.

Getting paid: best practices for contractors

• Invoice the same day you deliver — every day you wait is a day you delay your own payment
• Use Stripe or PayPal — clients pay significantly faster when you remove friction. A link in the invoice PDF means one-click payment
• Follow up professionally on the due date — not after. A brief reminder email surfaces your invoice at exactly the right moment
• Keep a payment log — track invoice date, due date, and actual payment date for every invoice. This data is invaluable for tax time and for spotting slow-paying clients early

When a client doesn't pay

If an invoice goes overdue, follow this escalation path:

1. Day 1 overdue: Friendly email reminder with the invoice attached
2. Day 7 overdue: Follow up by phone or Slack/text in addition to email
3. Day 30 overdue: Formal written demand letter noting the balance, original due date, and any late fees per your contract
4. Day 60+ overdue: Consider small claims court (for amounts under your state's limit, typically $5,000-$25,000) or a collections specialist

The best protection against non-payment is a signed contract before work begins. A written agreement that specifies deliverables, payment schedule, and late fee policy gives you legal standing if things go wrong.