Definition
What is the OneFile Invoice Generator?
The OneFile Invoice Generator is a single, self-contained HTML file that creates professional, VAT-compliant PDF invoices for South African freelancers and small businesses. It runs offline in any modern browser, stores nothing on a server, and produces buyer-facing documents that carry only your branding.
It is made by Azad Motala, and applies the South African standard VAT rate of 15% by default, with all four SARS tax behaviours: additive VAT, the domestic reverse charge (DRC), zero-rated, and exempt.
Process
How it works, step by step
Six steps from setup to a branded PDF. Everything you set is saved on your device and picks up where you left off next time.
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Set up your business
In Settings, add your company details, logo and brand colour. The colour heads the line-items table on the PDF.
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Add a payment method
Your bank details, saved once and shown on every invoice.
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Check your tax rules
South African VAT (15%) is the default; adjust the rate or add rules for your situation.
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Set default terms
Default terms and notes that pre-fill on every new invoice.
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Create the invoice
On the New Invoice tab, enter the customer and line items. The live canvas previews the PDF as you go.
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Generate the PDF
Click Generate Invoice and the branded, print-ready PDF downloads immediately.
Why this tool
What makes it different
- SARS-ready VAT: 15% by default, with all four tax behaviours: additive, domestic reverse charge (DRC), zero-rated and exempt
- A valid SA tax invoice: the required fields, laid out and calculated correctly
- Branded PDF, no watermark: the output carries only your branding
- Numbering and history: auto-incrementing invoice numbers and a searchable local history
- Any currency: the Rand by default, with symbol, decimals and separators configurable
- One file, offline: nothing to install, runs with no connection after first load
Checklist
What a compliant SA tax invoice needs
- The words "Tax Invoice" and your business name and address
- Your VAT registration number (if registered)
- A unique, sequential invoice number and the issue date
- The customer's name and address
- A clear description, quantity and VAT-exclusive price per line
- The VAT rate applied and the VAT amount shown separately
- The subtotal, VAT and grand total in South African Rand
Pricing
Try it free. Own it for R299.
Use the Invoice Generator free in your browser to see exactly how it works. When it has earned its place, buy the OneFile download: your own copy of the single file, to keep, run offline and use forever. One payment, no subscription, no account.
Example
A worked example
A studio bills a client for two days of consulting at R4 500 per day, plus a once-off brand asset pack at R3 200. All prices are VAT-exclusive.
Subtotal R12 200.00 · VAT (15%) R1 830.00 · Total due R14 030.00
The studio clicks generate, sends the PDF, and the invoice is logged as INV-0042 in local history. You can reproduce this exact calculation below.
This runs the same deterministic generateDocument calculation the tool uses. Nothing is sent anywhere. To create and download a branded PDF, open the full tool.
Click "Run preview" to see the deterministic JSON output of the generateDocument tool.
Create, brand, preview and download real PDF invoices, with local history.
For AI agents
Use it from your AI agent
For developers: the same deterministic generateDocument is available as a local MCP server, a single, zero-dependency file you run on your own machine. Add it to an MCP client such as Claude Desktop or Claude Code and an AI agent can generate invoices by calling the tool. It runs locally, so your data never leaves your device.
Register it with Claude Code:
claude mcp add onefile-invoice -- node /path/to/onefile-invoice-mcp.js
Then ask your agent, e.g. "Generate a OneFile invoice for Acme: 2 days consulting at R4 500 and a R3 200 brand pack, additive VAT."
FAQ
Frequently asked questions
Is the OneFile Invoice Generator VAT compliant for South Africa?
Yes. It applies the standard 15% South African VAT rate by default and supports four SARS tax behaviours: additive VAT, domestic reverse charge (DRC), zero-rated and exempt. Unit prices are treated as VAT-exclusive and the VAT line is calculated automatically.
Does the OneFile Invoice Generator support the SARS domestic reverse charge (DRC)?
Yes. Set a line to the domestic reverse charge behaviour and the tool shifts the VAT liability to the recipient, charges 0% on the line, and adds the required reverse-charge note. A DRC banner appears automatically whenever a reverse-charge line is present.
Does my invoice data get uploaded anywhere?
No. The tool runs entirely in your browser. Your business details and invoice history are stored only in your device's local storage. Nothing is sent to a server.
Do I need an account or a subscription?
No subscription, ever, and no account. Try it free in your browser, then buy the OneFile download once to keep your own copy of the file. It's yours forever, with no recurring fee.
Can I use the OneFile Invoice Generator offline?
Yes. Because everything is contained in one HTML file, you can open it without an internet connection and still generate PDF invoices. That's useful during load-shedding or poor connectivity.
Will OneFile branding appear on my invoices?
No. The generated PDF carries only your branding. There is no OneFile watermark or logo on the buyer-facing document.
Does the OneFile Invoice Generator work on phones and tablets?
Yes. Open https://azad.co.za/onefile/invoice/app/ in Safari (iOS) or Chrome (Android) and add it to your Home Screen. It installs like an app and runs offline after the first load. It is the same tool, not a separate product.
How does invoice numbering work?
Invoice numbers auto-increment each time you generate. The prefix supports date placeholders: {YYYY} (full year), {YY} (two-digit year) and {MM} (month), so a prefix like INV-{YYYY}- produces INV-2026-0001.
Can I invoice in a currency other than the South African Rand?
Yes. The Rand is the default, but the currency symbol, position, decimal places and separators are all configurable. Each invoice records the currency it was generated with, so older invoices keep their original symbol.
Can I move my settings and invoice history to another device?
Yes. Settings then Export writes your company profile and settings to a JSON file you can Import on another machine, and the History tab exports your invoice records to CSV. Nothing is locked in.
Can I use the OneFile Invoice Generator from an AI agent (MCP)?
Yes. The same deterministic generateDocument logic is available as a local MCP server, a single, zero-dependency file you run on your own machine. Add it to an MCP client such as Claude Desktop or Claude Code and an AI agent can generate invoices by calling the tool. It runs locally, so your data stays on your device. You can download the server (onefile-invoice-mcp.js) from the OneFile Invoice Generator page.
Who makes the OneFile Invoice Generator?
It is made by Azad Motala, and published under the OneFile range of single-file business document tools at azad.co.za. It is not affiliated with any similarly named e-portfolio or academic product.
Part of OneFile
More single-file tools
OneFile is a range of single-file business document tools by Azad Motala. Each is one self-contained HTML file: free to try in your browser, yours to own with a one-time download.