How to write an invoice that actually gets paid
Written for people who do the work and the billing. No accounting theory, just what goes on the document and why each part matters to the person paying it.
An invoice needs nine things: your business details, the customer details, a unique invoice number, the issue date, a due date, itemized lines with quantities and rates, the total, any tax, and how to pay you. Everything else on an invoice is optional, and most of what delays payment is one of those nine being missing or unclear.
The nine things every invoice needs
Every invoice that gets paid without a phone call contains the same nine elements. Work through them in order and you have a valid, readable document.
- Your business details. Trading name, contact email or phone, and any licence or registration number your trade requires.
- The customer's details. The name of the person or company who owes the money, and the address the work relates to if it is different.
- A unique invoice number. Sequential, never reused. This is what everyone quotes when there is a question.
- The issue date. The date the invoice is created, which is also the date your payment terms start counting from.
- The due date. An actual date, not a phrase. More on why below.
- Itemized lines. Description, quantity, unit rate and line total for each thing you are charging for.
- The subtotal and total. What is owed, in the currency you expect to be paid in.
- Tax, if you charge it. Shown as its own line with your tax registration number where your country requires one.
- How to pay. Bank details, a payment link, or the fact that it was already paid on site.
The word invoice should also appear on the document. It sounds obvious, but a page headed with only your logo and a total reads as a quote to an accounts department, and it will sit in a pile until someone asks.
Invoice numbers, and why they matter more than they look
An invoice number is a unique reference that must never repeat, and the simplest system that works is sequential: 1001, 1002, 1003.
Two rules make numbering painless. First, do not restart the sequence each year unless your accountant asks you to, because reused numbers create genuine confusion when an old invoice resurfaces. Second, do not leave gaps on purpose. A gap looks like a missing invoice to anyone reviewing your books, and explaining that you skipped 1007 because you did not like the number is a conversation nobody wants.
If you invoice several trading names or work through an agency, a short prefix helps. INV-1001 for your own work and MNT-1001 for a maintenance contract keeps two streams separate while both stay sequential. What matters is that the number is unique, findable and quotable over the phone.
How to word a line item so it does not get questioned
A good line item says what was done, how much of it, and at what rate, in the customer's language rather than yours.
Compare two versions of the same charge. "Labour, 480" tells the customer nothing and invites a question. "Fault finding and repair to kitchen ring circuit, 4 hours at 120" tells them what they bought, and it is the same money. Vagueness is what gets queried, not the amount.
Three habits do most of the work here:
- Split labor from materials. Customers accept both when they can see both. Folded together, the labor rate looks inflated.
- Use quantities. Six devices at 65 is easier to accept than a single line reading 390.
- Name the location or asset. Kitchen circuit, second floor washroom, rear boundary fence. It converts an abstract charge into a specific job.
Avoid internal shorthand. Your notebook can say "T and M, 2nd fix". The invoice should not, because the person paying it has never heard those words. Trade specific wording that customers do understand is covered on the trade pages, which show how each trade phrases its own lines.
Issue date, due date and payment terms
Put a real due date on the invoice, not a phrase, because a date is a deadline and a phrase is a suggestion.
"Payment due on receipt" is the most common wording in small business invoicing and one of the weakest. Received when? Nobody diaries it, so it drifts. "Due 18 August 2026" is a line an accounts clerk can act on, and it is what makes a later reminder reasonable rather than awkward.
Your terms decide the gap between the two dates. Net 7, net 14 and net 30 are the common choices, and the right one depends on who you are billing rather than what you prefer. Domestic customers usually pay faster than companies, and large companies pay on their own run regardless of what you write. The full detail is in the guide to invoice payment terms.
One thing to hold onto: the clock starts on the issue date. An invoice written four days after the job finishes has already given away four days of your own money.
Tax, without pretending there is one global rule
If you are registered for a sales tax such as VAT or GST, it goes on the invoice as its own line with your registration number, and if you are not registered, you do not add tax at all.
Beyond that, the rules genuinely differ by country and sometimes by state, and anyone telling you otherwise on a marketing page is guessing. Registration thresholds, what counts as a taxable supply, whether materials and labor are treated the same, and what a compliant invoice must show are all local questions. Ask an accountant in your own jurisdiction once, then apply the answer consistently.
What is universal is presentation. Show the net amount, show the tax as a separate line with the rate, and show the gross total. A customer who can see the split will not ask you to break it down later, and a tax authority reviewing your records will find what it expects.
Six mistakes that quietly delay payment
Most late payment is not refusal. It is friction, and nearly all of it comes from the same handful of errors.
- No purchase order number when the customer's system requires one. Some accounts departments will not process the invoice at all, and they will not always tell you.
- Sending it to the wrong person. The manager who hired you is often not the person who pays. Ask who invoices go to before you leave site.
- A total with no breakdown. One line invites one question, and that question takes a week to come back.
- No due date. Without one, nothing is ever late, which means nothing is ever urgent.
- Missing bank details. Obvious, common, and it turns paying you into a task that needs a reply first.
- Sending it days later. The job is fresh in the customer's mind for about forty eight hours. After that you are competing with everything else in their week.
When an invoice does go past its date, the fix is a process rather than a stronger email. There is a full script based approach in the guide on chasing an unpaid invoice.
What format to send it in, and how
Send a PDF. It looks the same on every device, it cannot be edited by accident, and it is what every accounts system expects to receive.
A spreadsheet or a photo of a paper invoice both technically work and both create friction. Spreadsheets reformat, images cannot be searched or filed, and neither looks like the work of a business that expects to be paid on time. Presentation is not vanity here. It changes how quickly the document is treated as real.
How you deliver it depends on the customer. Email is the default for companies, because it lands where their filing happens. For domestic customers, WhatsApp is often faster, since the message is read within minutes rather than at the end of the week. Sending the same PDF both ways is fine, and for a customer who is standing in front of you, doing it before you leave is the single most effective habit in this guide.
If you want a starting point rather than a blank page, there is a free invoice template here, and the trade specific pages show completed examples with realistic line items.
Questions that did not fit above
Do I legally have to issue an invoice?
It depends on your country and on whether you are registered for a sales tax, so treat this as a local question for your accountant. In practice, issuing a numbered invoice for every job is the right habit regardless, because it is your record of what was owed, what was paid and when.
What is the difference between an invoice and a receipt?
An invoice asks for money and a receipt confirms money was received. The same document can do both: once you record the payment against it, the invoice shows the amount paid and a zero balance, which is what a receipt is.
Can I invoice without a company or a registered business?
In most places a sole trader can invoice under their own name, and the invoice still needs the same nine elements. What differs by country is registration and tax, which is worth confirming locally rather than assuming.
Should I number invoices per customer or across the whole business?
Across the whole business. Per customer numbering produces duplicate numbers, which is exactly what the number exists to prevent. If you want to see one customer at a time, filter rather than renumber.
How long should I keep copies?
Longer than feels necessary, and the exact period is set by your local tax rules, commonly several years. This is one of the arguments for cloud backup rather than a phone that will be replaced twice in that time.
The same paperwork, trade by trade
The trade pages show Invoice Local doing this in context, with real line items and the wording each trade uses. There is also a free invoice template if you would rather start from a blank document.
The document matters less than how fast it goes out
Invoice Local builds all nine elements for you and sends the PDF in about thirty seconds, from an Android phone or any browser. Free forever for unlimited invoices and quotes.