An invoice is a request for payment for goods or services already delivered. It's not a quote (that's before the work) and not a receipt (that's after payment). The difference matters — mislabeling an invoice is one of the fastest ways to look unprofessional.
A good invoice does three things: identifies who owes what, makes it easy to pay, and creates a legal record if you ever need to collect. Miss any of those and you're slower to get paid.
1. Include the required fields. Every invoice needs the same core information, whether you write it on a napkin or generate it in an app. Miss a field and a customer has an excuse to delay.
2. Number invoices sequentially. Invoice numbers exist so you and the customer can reference a specific bill. Any sequential system works — 1001, 1002, 1003 or 2026-001, 2026-002. Avoid gaps (auditors flag them) and never reuse a number.
3. Write clear line items. The single biggest reason invoices get disputed is vague line items. 'Services rendered — $850' invites questions. '3 hours labor @ $95/hr + 2 replacement filters @ $137.50 each = $845' does not.
4. Set clear payment terms. 'Net 30' means payment due 30 days from the invoice date. 'Due on receipt' means today. 'Net 15' means 15 days. For trades and small services, due on receipt or net 7 is normal — you did the work today, you don't need to finance them for a month.
5. Deliver so the customer sees it. Email is standard but easy to miss. SMS gets a 98% open rate and averages a 3-minute response. If the customer replies to texts about the job, send the invoice by text too.
Frequently asked questions
Can I create an invoice for free?
Yes. Glo Invoice's free invoice generator lets you create and download a PDF at no cost. Paid plans add SMS/email delivery, card payments, and reminders.
Do I need to charge sales tax?
It depends on your state and whether you're selling goods (usually taxable) or services (varies by state and service type). Check your state's Department of Revenue or use our sales tax guide.
What's the difference between an invoice and a bill?
Same document, different perspective. It's an invoice to the sender and a bill to the receiver. Some businesses use 'statement' for a running summary of multiple invoices.
How soon should I invoice after finishing a job?
Same day if possible, next business day at the latest. Every day of delay pushes payment out further and increases the chance the customer forgets details of the job.
