24 September 2026 · 6 min read
Fundamentals
What Should an Invoice Include? The Complete 12-Point Checklist
Almost every invoice dispute comes down to a missing field, not a disputed price. This is the checklist a finance team actually runs before releasing a payment — twelve items, in the order they check them, plus the questions that trip people up most.
The 12-point checklist clients actually run
Print this list, keep it beside your desk, and run it before every send. These are the twelve items a client's bookkeeper looks for, roughly in order, before your invoice joins the payment run.
| # | What must be there | The mistake that delays payment |
|---|---|---|
| 1 | Your business name and contact details | A trading name that does not match the bank account the client must pay |
| 2 | Your VAT number, if you are registered | Omitted, so a VAT-registered client cannot use the invoice for input tax |
| 3 | The client's full legal name and billing address | An informal name, or the wrong branch, which fails their purchase-order matching |
| 4 | A purchase-order or reference number, where they use one | Left off the invoice, so it never attaches to their internal job record |
| 5 | A unique document number | Repeated or missing, which breaks their filing and your own records |
| 6 | The issue date | Backdated inconsistently with the work period |
| 7 | The due date | Replaced with vague wording, so nobody knows when to pay |
| 8 | Payment terms in plain words | A term the client never agreed to at the start of the job |
| 9 | Line items describing each deliverable | One lump line such as "services", which invites queries instead of payment |
| 10 | Quantity and rate for each line | Amounts with no visible arithmetic behind them |
| 11 | Discount and VAT shown as their own lines | Tax folded silently into a total, which the client has to unpick |
| 12 | Bank details plus a payment reference | Banking details only in an old email thread |
Required, recommended, and optional — three different questions
People argue about invoice content because they mix up three separate questions: what the law requires, what the deal requires, and what good practice recommends.
- Required by law: if you are registered for VAT in South Africa, a tax invoice must contain prescribed details — supplier and recipient information, a serial number and date, a description of what was supplied, quantity or volume, and the value, VAT and total. The VAT invoice requirements guide lists them properly.
- Required by your agreement: whatever you promised in the quote — the rate, the payment terms, the deposit, the deliverables. The invoice is where that promise becomes a request for money.
- Recommended by practice: numbering schemes, references, a clean layout. Not legislation — but the difference between a payment this week and a query next month.
Before and after: the invoice that came back
A plumber we will call Sipho finished a geyser repair worth R4,275 — a R950 call-out and R3,325 in parts. He wrote the first invoice in a notebook app on his phone: his name, the amount, and "due soon". It took two phone calls and five weeks to be paid, and the client's story was always the same — accounts could not process it.
The second invoice to the same client was barely more work to write, but it carried four additions: a document number (INV-0417), an issue date of 8 October 2026 with Net 7 terms and a due date of 15 October 2026, a description line split into call-out and parts, and the bank details with the invoice number as the payment reference. It was paid in four days.
Nothing about the work changed. What changed is that the client's admin could match, verify and pay the invoice without leaving the document — which is the entire job of an invoice.
What never belongs on an invoice
- The words "tax invoice" if you are not a registered VAT vendor — the term has a legal meaning in South Africa, and using it casually undermines it.
- A discount shown twice — once as a percentage on the line, once as a rand amount in the total — with no arithmetic that reconciles the two.
- Personal appeals or pressure ("please pay urgently, I have expenses"). The due date makes the case; the text should stay professional.
- Marketing that does not belong to this sale. Keep the document to the transaction; your brand can live in the header.
Where each field comes from in FreeInvoices
None of the checklist should be work you redo per invoice. In FreeInvoices each field has one home, and every new document inherits it:
- Your business details, VAT rate and payment details live in Settings and seed every new invoice.
- Clients live in Customers — pick one and their details (and VAT number) fill the invoice.
- Frequently billed lines live in Products and services; adding one copies it onto the line, where you can still edit it for this document only.
- Numbers, dates, terms and totals are computed in the editor as you type; the guide walks through the workflow.
How often to re-check your template
A stale invoice template is invisible until the day it costs you: a bank account that changed, an address that moved, a VAT status that changed and a document that still describes you as before. Run the twelve points once a quarter, and any time something about the business changes — a new bank account, a new business name, or VAT registration that starts or stops.
Frequently asked questions
Can an invoice be handwritten?
For most small suppliers there is no rule that an invoice must be printed. It must be complete and legible, and if you are a VAT vendor it must contain the prescribed tax invoice details. Handwritten invoices are harder to keep tidy in sequence, which is the practical reason most businesses type them.
Do I have to post a paper copy?
No — an emailed PDF is the normal way invoices change hands, and it gives you a dated record of delivery. What matters is the content of the document and that you keep your own copy; VAT vendors must retain records, including the tax invoices they issue, for five years.
What do I do if I notice a mistake after sending?
Send a corrected invoice with a new number that references the original, or a credit note if money was already paid. Never quietly overwrite a document the client has already filed — a clean trail of change beats a tidy-looking file.
Sources
The checklist is built into the editor: your details from Settings, the client from your list, lines from your catalogue, and totals computed as you type — then download the finished A4 PDF.
Start with the invoice editor