How to Make an Invoice: Format, What Goes On It, and How to Send One

What an invoice actually has to contain, how it differs from a quote, a proforma and a receipt, why Excel keeps costing people money, and how to produce one that gets paid.

An invoice is a request for payment that records what was sold, to whom, on what date, and what is owed. That is the whole of it. Everything else — the layout, the logo, the colour, the software — is decoration around those four facts.

Most guides to invoicing skip straight to a template. This one starts with what has to be on the page, because a beautiful invoice missing a due date is still an invoice you will be chasing in six weeks.

What is an invoice?

An invoice is a document a seller issues to a buyer that lists what was supplied and what is owed for it. It is issued after the work is done or the goods are sent, and it is the document the buyer pays against.

It is not a quote, a proforma, or a receipt, and using the wrong one is a common way to confuse a client into not paying. The four documents, in the order they normally appear:

• Quote (or estimate) — issued before the work. It offers a price. It is not a request for payment.
• Proforma invoice — issued before the work or the shipment. It shows what the invoice is going to say, so the buyer can arrange funds or clear customs. It is not a demand for payment and not an accounting record.
• Invoice — issued after the work or the delivery. It requests payment. This is the one that goes in the books.
• Receipt — issued after the money arrives. It confirms payment was received.

The distinction that catches people out is the proforma. A proforma invoice is a projection — it says "this is what I am going to bill you". It is common in import and export, where a buyer needs a document to open a letter of credit or clear goods, and in any job where the client's finance team needs a number before they can approve the work. It is not the invoice, and it should never carry the same number as one.

What has to be on an invoice?

At minimum, an invoice needs the following. If any of these are missing, the invoice is either unpayable or unusable as a record:

• The word "Invoice", so nobody mistakes it for a quote.
• A unique invoice number. One per invoice, never reused.
• The date it was issued, and the date payment is due. "Due on receipt" and "Net 14" are both fine; nothing at all is not.
• Who is billing. Your business name, address and a way to reach you.
• Who is being billed. The client's name and address — the legal entity, not just a person's first name.
• What they are paying for. A line per item: description, quantity, unit price, line total.
• The total owed, in a stated currency.
• How to pay. Bank name, account title, account number or IBAN — whatever a person needs to actually send the money.

Then, depending on your situation:

• Your tax registration number, if you have one.
• A tax line showing the rate and the amount, kept separate from the subtotal.
• Discounts, shown as a line rather than baked silently into the prices.
• Purchase order number, if the client works with POs. Leave it off and some finance departments will not process the invoice at all.

Invoice numbering, and why it matters more than it looks

Every invoice needs a number, every number must be unique, and the sequence should have no gaps you cannot explain. A missing number in a sequence is the kind of thing that turns a routine question into a longer conversation with an auditor.

A simple, durable scheme is a fixed prefix and a zero-padded counter: INV-0001, INV-0002, INV-0003. Zero-padding is not cosmetic — it keeps invoices sorting correctly in a folder or a spreadsheet, where INV-10 otherwise sorts before INV-2.

If you invoice enough to want the year in there, 2026-001 works and resets cleanly each January. What does not work is a number derived from the client's name or the date alone, because the moment you issue two invoices to the same client on the same day you have a collision.

What does an invoice format look like?

The standard layout, top to bottom, is: your details and logo at the top left, the word INVOICE and the invoice number, issue date and due date at the top right, the client's details below that, then the line items in a table, then the totals aligned to the right, and finally the payment instructions and any notes.

That order is not arbitrary. It puts the identifying information where somebody scanning a stack of paper looks first, and the total where the eye lands last. Any format that does those two things is a good format.

For the table itself, four columns is the sensible default: description, quantity, unit price, amount. Adding more — SKU, unit of measure, tax per line — is worth it only if somebody actually needs the extra column.

Should I make an invoice in Excel or use an invoice generator?

Excel is fine for a handful of invoices a year and starts costing you money beyond that. The failures are specific and they repeat:

• The numbering drifts. Copying last month's file and editing it is how two invoices end up sharing a number.
• Formulas break. A row inserted in the middle of the table, and the total silently stops including it. The invoice looks right and is wrong, which is the worst combination.
• Rounding goes wrong. Spreadsheets store money as floating-point numbers, so a column of prices ending in .10 or .70 can total to a figure a cent or a paisa off. Nobody notices until a client's accounts department does.
• The PDF is an afterthought. Exporting to PDF from a spreadsheet is where column widths, page breaks and stray gridlines go wrong.
• The old client's details are still in it. Duplicating a file and forgetting to change a name is how Sarah's invoice reaches John.

A generator removes most of that by construction: the number advances on its own, the arithmetic is not yours to break, and the output is a PDF laid out for the page rather than a spreadsheet squeezed onto one.

The honest case for Excel is that you already have it, you understand it, and for two invoices a quarter that is a real answer. The case against is that every one of the failures above is silent.

How do I add sales tax or GST to an invoice?

Show tax as its own line, never folded into the item prices. The invoice should read: subtotal, then discount if there is one, then tax calculated on the discounted amount, then any shipping, then the total.

The order matters, and it is a genuine source of disputes. A 10% discount and 17% tax applied in the other order produce a different total, and the client's accountant will apply them in the order above.

Two things to be careful about:

• Round the tax once, on the taxable total — not on each line and then added up. Rounding per line and summing can land a rupee or two away from the correct figure, and on an invoice that has to reconcile against a payment, a rupee is a phone call.
• Whether you must charge tax at all, at what rate, and what has to appear on the document, depends on your registration status and what you sell. That is not something a blog post can answer for you, and the rules change. Check the current requirements with the FBR, or with whoever does your filing, before you put a tax number on an invoice.

If you are not registered, do not put a tax line on the invoice at all. An invoice that shows tax you are not entitled to collect is a problem, not a formality.

How do I get paid faster?

Make the payment instructions impossible to miss and the due date specific.

• Put the bank details on the invoice itself, not in the email. Invoices get forwarded to a finance person who never sees your covering message.
• Give a date, not a duration. "Due 21 September 2026" is acted on. "Net 14" requires the reader to work out when that is, and something that requires arithmetic gets postponed.
• Include the invoice number in the payment reference line you ask for. It is how the payment gets matched back to the invoice without anybody emailing you.
• Send it the day the work is finished. An invoice sent a fortnight late signals that the deadline is soft.
• A QR code on the invoice saves the client typing a long bank account number off a screen, which is where transposed digits and bounced transfers come from.

Do I need to keep a copy?

Yes, and this is the part people get wrong when they switch tools. Whatever you use, the PDF you send is the record. Download it and keep it somewhere you will still have access to in a few years — a folder that syncs, not a browser tab.

Tools change, subscriptions lapse, and companies shut down products. A PDF on your own disk outlives all of that.

How do I make an invoice with my logo on it?

Any tool worth using will take a logo, but two things separate the ones that look professional from the ones that look homemade:

• The logo keeps its own proportions. A wordmark is wide and a monogram is square. A tool that stretches either to fill a fixed box produces something visibly wrong, and the client notices before they notice anything else.
• The colour carries through the document — the rule under the header, the table heading, the line above the total — rather than the logo sitting on an otherwise generic page.

Making one now

Lonecto's invoice generator does the above in the browser. Nine templates, your logo at its own proportions, your accent colour, eighty-nine currencies formatted the way each is actually written, tax and discount applied in the order accountants apply them, and automatic numbering that advances when you download.

It is free, there is no account, and the invoice is built on your device — so who you bill and what they owe never reaches a server. Each page carries one small line at the foot saying it was built with Lonecto. That is the whole of the catch.

If you are selling on Instagram or WhatsApp and invoicing is only part of the problem, taking orders properly on WhatsApp and how cash on delivery actually works are the two things that will move your numbers more than the invoice ever will.

Questions

What is the difference between an invoice and a bill? They are the same document seen from two sides. The seller issues an invoice; the buyer calls the thing they received a bill.

Can I invoice without being registered for tax? You can issue an invoice as a record of what is owed. Whether you must register, and whether you may charge tax, depends on your circumstances — check with the FBR or your accountant rather than a template.

What does "proforma" mean on an invoice? It means the document is a projection of what will be invoiced, not a request for payment. Give it its own numbering so it can never be mistaken for the real invoice.

Does an invoice need a signature? Usually not. Some clients ask for one on the document; a signature line costs nothing to add if they do.

What is the correct invoice number format? Any format that is unique, sequential and has no unexplained gaps. INV-0001 upward is the safe default, and zero-padding keeps it sorting properly.