Nobody is taught this. That is not a figure of speech — it came up verbatim in the research we did for this product, from someone trying to invoice their first photography job:

I'm new at the whole making money with photography and I don't exactly know how to write these. Still in high school and well Calculus doesn't seem to be applying to life very much. They should really teach stuff like this in school.

And from someone taking their first custom cake order:

I'm a little nervous and not sure what to include but I want to make sure all of my bases are covered.

So here is the reference, field by field, sorted into what an invoice genuinely needs, what is worth adding, and what varies by country. If you are sending your very first invoice and want the gentler version with context around it, read your first invoice: what actually has to be on it instead — this post is the checklist you come back to.

One disclaimer up front and then we will not repeat it: this is general guidance, not legal or tax advice. What must legally appear on an invoice genuinely differs between countries, and sometimes between regions inside one country, especially once sales tax, VAT or GST registration is involved. The list below is the widely accepted commercial shape of an invoice. For the specifics of your jurisdiction, check your own tax authority's guidance or ask an accountant once.

The eleven things that belong on every invoice

1. The word "Invoice"

Genuinely. An invoice has to be distinguishable from a quote, an estimate, a proforma or a receipt, because those four things have different consequences for whoever receives them. If a client's accounts department cannot tell at a glance that your document is a payable invoice, it will not get paid on this cycle. Put the word at the top.

2. Your business name and contact details

Your registered business name if you have one, your own legal name if you do not. An email address at minimum; a phone number and postal address if you have them and are comfortable sharing them. If you trade under a name that is not your legal name, showing both is the safe version.

This is also where a company number, tax registration number or professional registration goes, if you have them. If you do not have them, leave the fields off entirely — an empty labelled field looks worse than no field, and inventing a plausible number is a real problem rather than a cosmetic one.

3. The client's name and contact details

The company name if you are billing a company, the person's name if you are billing a person. Get the legal entity right: "Northside Media Ltd" and "Northside Media Group" may be two different companies with two different bank accounts, and an invoice addressed to the wrong one can legitimately be bounced.

If a finance department pays it rather than the person who hired you, ask who it should be addressed to and where it should be sent. "Accounts Payable" plus the company name is a completely normal answer.

4. A unique invoice number

One number, never reused, ideally sequential. Any scheme works: 001 upward, or 2026-001, or a short client prefix. What matters is that both of you can say "invoice 014" and mean exactly one document.

Two practical notes. Do not start at 1047 to look busier — nobody checks, and it will confuse your own records at tax time. And do not leave gaps on purpose; sequence is the thing that makes your invoice numbers useful as an income record.

This is also the single most tedious field to maintain by hand, which came up in the research from someone running invoices off a template:

its just a pain to go in and change the date, invoice number, client name+address+phone number, charges and brief description on each invoice.

That is the entire reason invoicing software exists. Charming Invoices claims the next number in your sequence at the moment you send, with your own prefix and padding, so the sequence stays gapless whether or not you end up sending every draft you started.

5. The issue date

The day you are issuing it. This is the date your payment terms count from, and it is usually the date the invoice lands in your accounts for the tax year, so do not backdate it casually.

6. The due date

An actual date, not just a phrase. "Net 30" means payment is due 30 days from the issue date, and it is completely standard, but your client's accounts system wants a date and your future self chasing it wants a date too. The clearest form shows both: "Due 14 November 2026 (Net 30)."

For choosing the interval: Net 14 is reasonable for individuals and small clients who pay out of one account, Net 30 is normal for larger companies that run payment cycles. One person in the research made a point about Net 30 worth internalising before you pick it:

Net 30 terms mean your first chase is on day 31. By then the invoice is old news, forgotten, ignored etx... or maybe the project is a distant memory?

7. A clear description of the work or goods

One line per thing, in language your client would recognise. "Brand identity — three logo concepts, two revision rounds" beats "Design services." "Sourdough loaves, 7 dozen, October 18 wedding" beats "Catering."

Vague descriptions are the leading cause of the "can you clarify this?" email, and that email costs a week. Write the line as though it will be read by someone who was not in any of your meetings, because it will be.

8. Quantity, unit price and line total per line

Hours, days, items, words, images — whatever you actually sell — then the rate, then the arithmetic. The point is that the final number should be checkable. A total that can be verified reads as a price; a total that appears from nowhere reads as an opinion, and opinions get queried.

A flat project fee is fine too: quantity 1, unit price the fee. You are not obliged to itemise your hours.

9. Subtotal, then tax and discounts, then the total due

Show the build. Subtotal of all lines, then any discount, then any tax as its own line with its rate stated, then the total. One final figure, unambiguous, ideally the most prominent number on the page.

If you are not registered to charge sales tax, VAT or GST, do not add a tax line and do not charge tax you are not registered to collect. Leaving it off is correct.

10. The currency

Obvious until it is not. "1,400" on an invoice from a British designer to a US client is a 25% ambiguity. Name the currency explicitly — USD, GBP, EUR — not just a symbol, since the dollar sign alone is used by a couple of dozen currencies.

11. How to pay you

The field people forget, and the one that actually delays payment. Bank transfer details with whatever your country uses (account and routing number, sort code, IBAN and BIC), or a payment link, or both. Be explicit about anything they need to include, such as a reference.

If you accept more than one method, say which you prefer. A client given three options sometimes picks none.

Worth adding, not strictly required

A payment reference, and a purchase order number if there is one. This is the unglamorous field that saves the most arguments later. From someone in the research who had hit the wall:

The painful part isn't invoicing, it's reconciliation, especially when clients batch payments or don't use references.

If your client works with purchase orders, ask for the PO number before you invoice and put it on the document. On some clients' systems an invoice without one simply cannot be paid, and nobody will tell you that — it will just go quiet.

What the payment covers, and any conditions attached. A deposit invoice should say what the deposit holds: "This retainer secures 14 June 2027." A licensing invoice should say what the licence permits and when it takes effect. These belong on the invoice and not only in the contract, because the invoice is the document that reliably gets opened.

Late payment terms, if you have agreed them. A late fee or interest charge is only worth printing if you mentioned it before the work started. Appearing for the first time on the invoice, it reads as a threat and is usually unenforceable anyway. Mentioned up front, it does real work, as someone put it in the research:

I put a late fee on the invoice up front so there's no arguing about it later.

An early payment discount, if that suits your cash flow. Common enough in some markets to have its own word — German speakers in the research used "Skonto" for it.

A short thank-you line. Costs nothing, and the invoice is the last document in the project.

Your logo. Not decoration. A document that looks considered gets treated as routine rather than as a request, which is most of why we care about how invoices look.

Depends on where you are

These are the fields where you should actually check rather than copy a template off the internet:

Tax registration numbers. If you are VAT or GST registered, your number almost certainly has to appear, and often your client's does too for cross-border work. There are usually required wordings for reverse charge and zero-rated supplies.
Required phrases and formats. Several countries specify exactly what a compliant invoice must contain, and some now mandate structured electronic invoicing for business-to-business or government work.
Retention periods. How long you must keep copies varies, and it is typically measured in years.
Company details for registered companies. Registered office address, company registration number and similar are mandatory on commercial documents in some jurisdictions.
How long payment may legally take, and what interest you may charge. Some places set statutory limits and a statutory interest rate.

None of that affects the eleven-item list above, which is the commercial shape of an invoice everywhere. It affects what you may have to add to it.

Leave these off

Tax numbers you do not have. Covered above, worth repeating.
A client's full card details or bank credentials. You should never be holding these, let alone printing them.
More personal data than the invoice needs. A client's home address on an invoice to their employer, for instance.
Internal notes. The margin, your opinion of the brief, your shorthand for the client. Someone will read it.
Apologies. "Sorry for the delay in sending this" and "no rush on payment" both undercut the document. Asking for money without the awkwardness goes into why.
Anything you have not agreed. An invoice is not the place to introduce a new charge for the first time.

A finished invoice, in order

Reading top to bottom, a conventional invoice looks like this:

Your name or logo, and your contact details.
The word "Invoice", the invoice number, the issue date, the due date.
Who it is for, and a purchase order or reference number if there is one.
The line items: description, quantity, unit price, line total.
Subtotal, discount, tax, total due in the stated currency.
How to pay, and by when.
Terms and notes: what the payment covers, late payment terms, thank you.

That list is more or less the shape of Charming Invoices, which is not a coincidence — the product is this reference with the arithmetic done for you, your branding on top, and a private link your client can open without creating an account. The one item without a dedicated field of its own is the purchase order or reference number; put it in the invoice's notes, which are printed on the document and on the public view. Unlimited invoices and clients on the free tier, which exists so that getting the first one out does not require a decision about money.

But the format matters less than the sending. A plain invoice with these eleven things on it, sent today, beats a perfect one you are still fiddling with on Friday.