What Must Appear on an Invoice in the US? A State-by-State Guide

Is there a federal invoice format in the United States? No. Unlike most European countries, the US has no unified federal invoicing law that dictates what an invoice must contain. However, that does not mean invoices are unregulated. Sales tax rules vary by state and often require specific information on invoices. The IRS imposes 1099 reporting requirements that depend on how invoices are structured. And certain industries have their own documentation standards. This article explains what matters in practice, the most common mistakes, and the key 2026 changes to be aware of.

What belongs on a US invoice

While no single federal statute prescribes invoice fields, a combination of IRS requirements, state sales tax laws, and commercial best practices means a properly structured invoice should include the following:

Seller identification: your legal business name (as registered with the IRS), business address, and Employer Identification Number (EIN) or Social Security Number for sole proprietors. If you are registered for sales tax in a state, your state tax permit number should appear as well.

Buyer identification: the customer’s name and address. For B2B transactions, the customer’s EIN or tax ID may be needed — particularly if they provide a resale certificate or claim a sales tax exemption.

Invoice details: a unique invoice number, the invoice date, payment terms (Net 30, due on receipt, etc.), and a detailed description of goods or services with quantities and unit prices.

Sales tax: if applicable, the invoice must show the taxable amount, the sales tax rate, and the tax amount separately. In states that charge sales tax, failing to itemise tax on the invoice can create audit issues for both the seller and the buyer. Five states — Alaska, Delaware, Montana, New Hampshire, and Oregon — do not levy a statewide sales tax, though local jurisdictions in Alaska may impose one. In states with destination-based sourcing, the rate applied must match the buyer’s location, not the seller’s.

Exemption documentation: if the buyer claims a sales tax exemption (resale, non-profit, government entity), the seller should note the exemption on the invoice and keep the buyer’s exemption certificate on file. Without proper documentation, the seller bears liability for uncollected tax.

3 common mistakes

Not separating sales tax from the total. Many small businesses, particularly in service industries, invoice a lump-sum amount without separating sales tax. In most states that charge sales tax, the tax must be shown as a separate line item. Failing to do so can mean the entire amount is treated as taxable in an audit, resulting in additional tax owed plus penalties.

Ignoring nexus in multiple states. Since the 2018 Supreme Court decision in South Dakota v. Wayfair, states can require out-of-state sellers to collect sales tax if they exceed economic nexus thresholds (typically $100,000 in sales or 200 transactions). A business selling online to customers in multiple states must determine where it has nexus and apply the correct rate on each invoice. Using the seller’s home-state rate for all customers is a common and costly error.

Missing W-9 information for 1099 reporting. If you pay an independent contractor and later need to file a 1099-NEC, you need the contractor’s correct taxpayer identification number. The time to collect a completed W-9 form is before the first payment, not at year-end. Starting with payments made in 2026, the 1099-NEC and 1099-MISC reporting threshold has been raised from $600 to $2,000 under the One Big Beautiful Bill Act, but all income remains taxable regardless of whether a 1099 is issued.

Key 2026 changes

1099 threshold increase. The One Big Beautiful Bill Act, signed into law on July 4, 2025, raised the reporting minimum for Form 1099-NEC and Form 1099-MISC from $600 to $2,000, effective for payments made starting in the 2026 tax year. This means businesses only need to issue a 1099 to contractors paid $2,000 or more in a calendar year. The 1099-K threshold for third-party payment platforms has reverted to the original $20,000 and 200-plus transactions rule, eliminating the previously planned lower thresholds.

State conformity varies. Not all states automatically conform to the new federal threshold. Some states, like California, have adopted the $2,000 threshold. Others, like Mississippi and Wisconsin, retain the $600 threshold in their own statutes. Businesses operating in multiple states should verify each state’s current filing requirements.

The US has no federal e-invoicing mandate and none is currently planned. Some state and local governments accept or require electronic invoices for procurement, but there is no national equivalent to the European e-invoicing initiatives. However, the IRS continues to expand electronic filing requirements: for tax year 2025, businesses filing 10 or more information returns of any type must file electronically.

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