Nothing you type is sent to us.

Calculations and invoices

Every figure you enter — amounts, business names, ABNs, client details, line items — is processed by JavaScript on your own device. There is no upload step, so this data is never transmitted, never logged and never stored by us.

You can verify it: open your browser’s developer tools, switch to the Network tab, and build an invoice. No request is made.

What is stored on your device

• theme — whether you chose light or dark.
• calcgst.invoice.v1 — your business name, ABN, contact line, GST registration setting, and last invoice number, so you do not retype them.

Both live in your browser’s local storage, on that device only. They are readable by this site and nothing else, they never reach us, and clearing your browser data removes them.

Analytics

None at present. If that changes, this page will say so before it does, and will name what is collected.

Third parties

Fonts are served by Google Fonts, which receives your IP address as part of any request for a font file. No other third-party service runs on these pages.

Your rights

We handle personal information in line with the Privacy Act 1988 (Cth) and the Australian Privacy Principles. Because we do not collect or hold your data, there is generally nothing for us to return or delete — but you can ask at [email protected]. Unresolved complaints can be taken to the Office of the Australian Information Commissioner.

Not tax advice

These tools calculate and format. They do not advise. Whether you must register for GST, whether a sale is taxable, and how to lodge a BAS are questions for the ATO or a registered tax agent.

Changes

If this policy changes materially, the revised version is published here. Last updated 20 September 2026.