Invoicing guides

Short, practical answers for US small businesses and freelancers: what to put on an invoice, how to number invoices, which payment terms to use, and how to get paid on time.

How to Write an InvoiceTo write an invoice, put your business details and the client's details at the top, add a unique invoice number, the invoice date and a due date, then list each product or service with quantity, rate and line total. Finish with the subtotal, any sales tax, the total due, your payment terms and how the client can pay. Keep descriptions specific so the client can approve it without questions.
What Is an Invoice?An invoice is a document a business sends to a customer to request payment for goods or services it has provided. It lists what was delivered, the amount owed, the due date and how to pay. Once paid, the invoice also serves as a record of the sale for both sides.
Invoice vs. Estimate: What's the Difference?An estimate is an approximate price you give a client before work begins, and the final cost may change. An invoice is sent after the work is done (or at an agreed milestone) and requests payment for the actual amount owed. An estimate doesn't ask for payment; an invoice does.
Invoice vs. QuoteA quote is a fixed price offer you give a client before work starts, usually valid for a set period, such as 30 days. An invoice comes after the work (or at an agreed milestone) and requests payment of the amount owed. A quote doesn't ask for payment; once the client accepts it and you deliver, you send an invoice.
What to Put on an InvoiceEvery invoice should include your business details, the client's details, a unique invoice number, the invoice date and due date, itemized products or services with quantities and rates, the subtotal, any tax, discounts or deposits, the total due, and how to pay. Optional fields like a PO number, project name or a thank-you note make invoices easier to approve.
How to Number InvoicesGive every invoice a unique number that follows a consistent sequence, and never reuse or skip numbers without a reason. The simplest options are a plain sequence (1001, 1002, 1003) or a year-based format (2026-0001, 2026-0002). Pick one scheme, write it down, and stick with it.
Invoice Payment Terms ExplainedPayment terms tell your client when and how to pay an invoice. Common terms include due on receipt, net 15, net 30 (due 30 days after the invoice date) and early-payment discounts like 2/10 net 30. Agree on terms before you start work, then put both the terms and the actual due date on every invoice.
What Does Net 30 Mean?Net 30 means the client has 30 days to pay the full invoice amount, usually counted in calendar days from the invoice date. An invoice dated October 1 with net 30 terms is due October 31. Variations like 2/10 net 30 add an early-payment discount: 2% off if paid within 10 days, otherwise the full amount is due in 30.
How to Send an InvoiceSave the invoice as a PDF, then email it to the person who pays your bills with a clear subject line that includes the invoice number, amount and due date. Keep the email short and restate how to pay. If it's not paid by the due date, follow up politely the next day, then again about a week later.
Invoicing for Small Business: Setting Up Your ProcessA good small business invoicing process comes down to five decisions: a consistent invoice template, a numbering scheme, standard payment terms, a routine for sending and following up, and one place where you track what's paid, unpaid and overdue. Set these up once and every invoice after that takes a few minutes.