Offsetcheck

2026 — Present · Founder

Your bank does the calculating. We do the checking. Offsetcheck is an independent auditing tool for Australian homeowners — upload your mortgage/offset account statements and it recalculates daily interest and offset benefit right in your browser, flagging any gap between what your bank charged and what you should have owed.

Visit Offsetcheck → Offsetcheck screenshot

Outcomes

Built a client-side interest and offset-benefit recalculation engine — statements are processed entirely in the browser, nothing is uploaded or stored on a server.
Reconstructed daily balance and offset benefit from raw bank statement data to independently verify the bank's own interest charges.
Designed the audit to flag discrepancies between what was charged and what should have been owed, giving homeowners a concrete number to query with their bank.
Positioned around a simple promise — "keeping the bankers honest" — for a category (mortgage offset accounts) that almost nobody independently checks.

Skills & technologies

Client-Side Data Processing Financial Calculations Privacy-First Product Design Product Development Consumer Fintech Positioning & Brand Google Analytics Google Search Console Shipped MVP No data leaves the browser