Do US Invoices Have Legal Requirements?
Unlike the UK, the US has no federal law requiring invoices for most business-to-business transactions. However, invoices are essential for tax compliance, record keeping, and getting paid. And certain situations — like 1099 reporting, sales tax, and government contracts — do have strict requirements.
What Every US Invoice Should Include
While not all fields are legally mandated, the following are best practices that protect you and make you look professional:
✅ Best Practice Invoice Fields (US)
Your business name — Must match your legal entity (LLC, Corp, Sole Prop, or DBA).
Your business address — The address registered with the IRS or your state.
EIN (Employer Identification Number) — Required for 1099 reporting. If you're a sole prop without an EIN, use your SSN (but get an EIN — it's free from IRS.gov).
Client's business name and address — The legal entity name for their records and yours.
Invoice number — Unique and sequential. Helps both parties track payments.
Invoice date — The date you issue the invoice.
Payment due date — Net 30, Net 15, or Due on Receipt. Set expectations clearly.
Itemized description of goods/services — Be specific. "Website design — Phase 1" not "Work."
Quantity and rate — Hours, units, or flat fees. Show the math.
Subtotal — Before tax and discounts.
Sales tax (if applicable) — Varies by state. See Sales Tax section below.
Total amount due — The final number the client must pay.
Payment instructions — Bank transfer (ACH/wire), Stripe, PayPal, check, or credit card.
Late fee policy — Optional but recommended. "1.5% per month on balances past due."
1099 Rules: What You Must Know
When You Receive a 1099
If a client pays you $600 or more in a calendar year for services, they must file a 1099-NEC (Non-employee Compensation) with the IRS and send you a copy by January 31. Your invoice must include your EIN or SSN so they can file it correctly.
⚠️ Warning: If you don't provide your EIN/SSN on your invoice, the client may withhold 24% backup withholding from your payment. Always include your EIN.
When You Issue a 1099
If you pay a freelancer, contractor, or service provider $600 or more in a calendar year, you must issue them a 1099-NEC. You need their legal name, address, and EIN or SSN — usually collected via a W-9 form before the first payment.
Sales Tax by State
US sales tax is a state-level tax, not federal. Whether you charge sales tax depends on:
- Nexus — Do you have a physical or economic presence in the state? Most states have economic nexus thresholds ($100K+ revenue or 200+ transactions).
- Product vs. Service — Most states tax tangible goods. Some tax services (especially digital/software). Some don't tax professional services at all.
- Destination-based sourcing — In most states, you charge tax based on the client's location, not yours.
States That Tax Digital/Software Services (Select Examples)
- Texas — Taxes SaaS and digital services
- New York — Taxes digital products and some software
- California — Generally does NOT tax professional services (design, consulting, dev)
- Florida — Taxes digital products but generally exempts professional services
- Washington — Taxes digital products and SaaS heavily
💡 Tip: If you sell to clients in multiple states, consider using sales tax automation software (like TaxJar or Avalara) to calculate, collect, and remit correctly. Wrong sales tax handling can trigger state audits and penalties.
Special Cases
Interstate Commerce
If you sell goods across state lines, you generally charge sales tax based on the destination state's rules. The Streamlined Sales Tax Project (SSTP) helps simplify this for participating states, but compliance is still complex.
International Clients (Outside US)
For clients outside the US, you generally do not charge US sales tax. However, you may need to provide a W-8BEN form to prove you're a foreign person and avoid backup withholding. If you're a US business invoicing a foreign client, no US tax is typically withheld — but the client may have local tax rules.
Government Contracts
Government contracts often require specific invoice formats, certified payroll, and compliance with Prompt Payment Act rules (federal agencies must pay within 30 days or owe interest). Always read the contract's invoicing requirements.
Record Keeping
💡 Tip: The IRS recommends keeping all business records, including invoices, for at least 3 years from the date you filed your return. However, if you underreported income by more than 25%, they can go back 6 years. Keep digital copies. Cloud storage is acceptable and encouraged.