Invoicing guides
Plain-language guides to invoicing for freelancers, consultants, and small businesses: what belongs on an invoice, how to number it, which payment terms to use, and how to follow up when a client is late.
We build FreeInvoicePDF, so we spend a lot of time reading the invoices people put together in it. The same handful of questions come up: what has to be on the document, which number to give it, what Net 30 commits the client to, and what to do when the due date passes. These guides answer those questions in the order they usually come up on a job.
They are written for one-person and small teams billing other businesses. None of it is legal, tax, or accounting advice, and invoice requirements genuinely differ between countries, so treat local rules and your accountant as the final word. Where something depends on where you are, we say so instead of guessing for you.
Start with how to write an invoice if you are new to this, or the self-employed basics guide if you want the short version of fields, numbering, and filing. Use the numbering, payment terms, and deposits guides when you already know the basics but keep stumbling on one detail. The overdue email guide is for the week after the due date, when you need wording that is firm without being rude.
Later guides cover the fiddly middle of a job: invoice date versus due date, partial payments and open balances, hourly versus fixed-fee line items, and how to show expense reimbursement without muddying your fee. Jump to whichever matches the PDF you are stuck on.
When something goes wrong after you hit send, use revising or voiding for corrections, the disputes guide when the client challenges the work or the total, and the payment-methods guide so the next PDF lists clear ways to pay without another round of email.
How to write an invoice
A field-by-field walkthrough, from the invoice number to the payment details, with a fully worked total.
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Invoice numbering systems
Sequential, date-based, and client-coded numbering compared, plus how to handle a corrected invoice.
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Payment terms explained
The vocabulary clients expect, how to pick a term, and exact wording for deposits and late fees.
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Estimate, quote, invoice, and receipt
Which document to send at which point in a job, and why the label on it matters.
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How to get invoices paid on time
What to settle before the work starts, how to send the invoice, and a follow-up schedule with wording.
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Retainer and milestone invoices
Deposits, retainers, and staged billing, with line items and notes that keep the math honest.
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Discounts, tax, and totals on invoices
Subtotal, discount, tax, total: the order clients expect and how to write each line.
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Revising or voiding an invoice
Corrections, credit notes, and voids without reusing invoice numbers.
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How to invoice a deposit
Upfront deposits and balance invoices, with clear line items and notes.
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Overdue invoice email wording
A simple follow-up sequence with wording you can paste and send.
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Self-employed invoicing basics
The minimum fields, a simple filing habit, and where local tax rules take over.
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Invoice date vs due date
Issue date, due date, and Net terms, with worked examples so both sides count the same days.
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Partial payments and balances
Recording a partial pay, invoicing the rest, and noting prior payments without confusing finance.
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Hourly vs fixed-fee invoices
Choosing a billing style, writing hours or package lines, and mixing both without muddying the total.
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Expense reimbursement on invoices
Billing travel, materials, and other pass-through costs with receipts and clean line items.
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What to do when a client disputes an invoice
How to respond to a dispute without panicking, rewriting history, or freezing forever.
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Writing invoice line item descriptions
Clear descriptions, quantity and rate patterns, and wording that survives a PO match.
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Choosing payment methods to list on invoices
Pick a few clear options, write the details once, and keep the notes field useful.
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Then make the document
When you are ready to send something, the invoice generator fills in and renders the PDF in this browser. There are ready-made starting points for freelancers, consultants, small businesses, contractors, photographers, tutors, babysitters, house cleaners, guest speakers, and paid invoices, plus a contractor estimate if the work has not been agreed yet.
These pages stay free forever and ad-supported. There is no account, no paywall, and no daily quota. Spotted something in a guide that is wrong or out of date? Tell us on the contact page. Tiny Utility Lab writes and maintains these pages, and we would rather fix an error than leave it up.