Invoice Guides
An invoice never exists on its own. It fulfils a purchase order, creates a receivable, carries tax, falls due under payment terms, and — in a growing list of countries — must be issued in a regulated electronic format. These guides explain that surrounding world.
Looking for a specific document type instead? The invoice types hub explains 27 of them. Need a quick definition? Try the glossary. Just need to bill someone? The generator is free.
Documents & Paperwork
Every sale generates a chain of documents. A quote or estimate proposes the deal. A purchase order authorises it. An invoice requests payment for it. A delivery note travels with the goods, and a receipt proves the payment happened. Each document has one job, and most billing disputes trace back to two of them being confused.
- Purchase Order vs Invoice: What Each Does and When to Use ThemOne document starts the purchase, the other ends it. Who issues each, and how they match up.Read the guide
- Estimate vs Quote: Which One Are You Actually Giving?One is a best guess, the other is a committed price. The difference decides what you can bill.Read the guide
- Delivery Notes: The Document That Travels With the GoodsWhat a delivery note proves, what goes on it, and how it feeds three-way matching.Read the guide
- Receipts: Proof of Payment, Not a Request for ItWhere receipts fit in the document chain, and why an invoice never doubles as one.Read the guide
Accounting
The moment you issue an invoice, it stops being a document and becomes an accounting event. It creates a receivable, it may recognise revenue, and it will eventually need to be matched against a payment.
- Accounts Receivable: The Money Your Invoices RepresentWhat AR is, how invoices create it, and how to keep it from quietly becoming bad debt.Read the guide
- Cash vs Accrual Accounting: When Does an Invoice Count?The two ways to answer "when did I earn this?" — and what each means for your invoices.Read the guide
- Bookkeeping Basics for People Who Send InvoicesThe minimum viable bookkeeping system for a freelancer or small business.Read the guide
- Double-Entry Bookkeeping: Why Every Invoice Touches Two AccountsDebits, credits, and what actually happens in the books when you issue an invoice.Read the guide
- Revenue Recognition: When Is the Money Actually Yours?Issuing an invoice and earning revenue are not the same event. Here is the difference.Read the guide
- The AR Aging Report: Reading the Age of Your Unpaid Invoices30, 60, 90 days: what the aging buckets mean and what to do about each.Read the guide
Payments
An invoice is only as good as the payment behaviour it produces. The terms you print on it, the payment methods you accept, and how you respond when a due date passes decide how fast money actually arrives.
- Net 30 and Friends: Payment Terms DecodedNet 30, Net 15, EOM, 2/10 Net 30 — what the shorthand means and which to choose.Read the guide
- Late Fees on Invoices: What You Can Charge and HowLate fees only work if they were agreed in advance and priced within the rules.Read the guide
- ACH vs Wire Transfer: Speed, Cost and When Each FitsTwo ways to move money between banks, priced and paced very differently.Read the guide
- Accepting Online Payments on Your InvoicesCards, wallets, bank buttons and QR codes — the trade-offs of each rail.Read the guide
- Partial Payments: Taking Money in Pieces Without Losing TrackDeposits, instalments and part-payments — recording them so the balance stays true.Read the guide
Tax on Invoices
Most invoices carry tax, and the rules for how it must appear are set by national tax authorities — which means they differ by country and change over time. These guides explain the concepts that recur everywhere: what consumption taxes are, how registration numbers work, and how prices are quoted with tax in or out.
- Sales Tax on Invoices: The US Model ExplainedState-set rates, nexus, and why US invoices tax differently from VAT countries.Read the guide
- Reverse Charge VAT: When the Buyer Accounts for the TaxWhy some B2B invoices carry no VAT and a "reverse charge" note instead.Read the guide
- Tax IDs on Invoices: VAT Numbers, EINs, ABNs and MoreWhich registration numbers belong on an invoice, and how to sanity-check them.Read the guide
- Tax-Inclusive vs Tax-Exclusive Pricing on InvoicesSame price, two presentations — and real consequences for totals and margins.Read the guide
Compliance
Invoicing is regulated. What an invoice must contain, how long you must keep it, and — increasingly — the technical format it must be issued in are all set by law, and the law is moving fast: a growing list of countries now mandates structured e-invoicing for business-to-business sales.
- E-Invoicing Mandates: Who Must Switch, Where, and WhenStructured e-invoicing is becoming law across the EU and beyond. The map and the timeline.Read the guide
- What Makes an Invoice Legally Valid?The fields the law cares about, and how requirements differ by country.Read the guide
- How Long to Keep Invoices: Retention Rules by PurposeTax audits, warranties and disputes each set their own clock. Keep the longest one.Read the guide
- Electronic Signatures on Business DocumentsSimple, advanced and qualified signatures — and whether invoices need one at all.Read the guide
- Peppol: The Network Behind Modern E-InvoicingHow Peppol moves structured invoices between businesses, and who has to use it.Read the guide
Invoice Basics
Every invoice moves through the same life: drafted, issued, received, approved, paid — or disputed, corrected and chased. Understanding that lifecycle is what turns invoicing from paperwork into a process you can manage.
- The Invoice Lifecycle: Draft to Paid, Step by StepThe stages every invoice passes through, and where each one can stall.Read the guide
- Invoice Dates: Issue, Supply, Due — and Why They DifferThree dates, three jobs. Mixing them up distorts tax periods and payment terms alike.Read the guide
- Invoice Status: What Draft, Sent, Overdue and Void Really MeanA shared vocabulary for where an invoice is in its life — and what flips each state.Read the guide
- Invoice Approval Workflows: How Buyers Decide to PayWhat happens to your invoice inside the client’s accounts payable process.Read the guide
- What to Include on an Invoice: Every Field, ExplainedThe anatomy of a complete invoice — required fields, useful extras, and what to skip.Read the guide
Where to Go Next
Invoice types
Proforma, commercial, credit note, GST — 27 document types explained, each linked to a matching template.
Browse invoice typesGlossary
Short, precise definitions of invoicing and accounting terms — each one routed to the deeper read.
Browse the glossaryHow-to articles
Practical walkthroughs — making an invoice, chasing late payment, adding tax, numbering done right.
Browse the blog