Contact Support & Feedback

Have questions, feedback, or advertising inquiries? We're dedicated to helping Australian taxpayers, businesses, and accountants calculate GST accurately.

Online Message Support

Quick Inquiry Form

Use our secure contact form on this page to send us a direct message. We review and respond within 1 business day.

Online Support Desk

gstcalcu.com Support

Dedicated digital tax calculation and invoice compliance utility.

Operating Hours

Monday to Friday: 9:00 AM – 5:00 PM AEST

Weekend queries are reviewed first thing Monday morning.

Official ATO Tax Inquiries

For official private tax rulings, ABN dispute resolution, or personal debt assistance, please contact the Australian Taxation Office directly on 13 28 66.

Send Us a Message

Fill out the form below and our team will get in touch with you shortly.

Frequently Asked Questions

Is this GST Calculator 100% free?

Yes. Our tool is completely free with no registration, subscription fees, or account creation required.

Does the calculator store my financial inputs?

No. All mathematical operations are calculated in real time locally within your web browser. No dollar figures or invoice numbers are sent to our servers.