Privacy Policy

Last Updated: September 2026 • Effective Date: Immediately

Our Privacy Guarantee: Zero Financial Input Storage

All numerical data you enter into our calculators (including initial investment principal, monthly contributions, interest rate targets, and years) is processed entirely locally within your web browser. We do not transmit, log, record, or store any of your financial amounts on our servers or databases.

1. Introduction & Data Controller

This Privacy Policy sets out how Compound Interest Calculator UK (referred to as “we”, “us”, or “our”, operating via compoundinterestcalculatoruk.co.uk) collects, handles, and protects information when you visit our website.

We are committed to preserving your personal data in accordance with the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act 2018. For the purposes of UK data protection law, we act as the Data Controller.

2. What Data We Collect

We believe in data minimisation. We collect only the minimum information necessary to ensure the site operates reliably and securely:

A. Calculator Numerical Data (Client-Side Only)

Any balances, interest rates, frequencies, or time horizons you input are processed entirely in client-side JavaScript. This data is never sent to our servers, never stored in cookies, and is permanently discarded when you close or refresh your browser tab.

B. Technical & Server Log Data

When you access our website, standard web server access logs are generated for network security, DDoS mitigation, and server performance monitoring. These logs may include your IP address, browser type, operating system, referring URL, and timestamps.

C. Direct Enquiries & Contact Form Submissions

If you choose to contact us via our contact form or support emails, we collect the name, email address, and message contents you provide solely to reply to your enquiry.

3. Legal Basis for Processing Under UK GDPR

Under Article 6 of the UK GDPR, we rely on the following lawful bases:

Legitimate Interests: To maintain website security, prevent fraudulent automated traffic, analyze aggregated website performance, and optimize user experience.
Consent: Where you opt in to non-essential analytical cookies (if applicable).
Legal Obligation: If required to comply with UK regulatory or law enforcement disclosure duties.

4. Cookies & Tracking Technologies

Cookies are small text files placed on your device by your web browser. Our site uses minimal cookies:

Cookie Category	Purpose	Duration
Strictly Necessary	Core CDN routing, security tokens, and server load balancing.	Session
Aggregated Analytics	Anonymous visitor counts to measure popular calculators and page performance.	Up to 12 months

You can manage or disable cookies at any time through your browser settings (Chrome, Safari, Firefox, Edge).

5. Your Rights Under UK GDPR

Under the UK Data Protection Act 2018 and UK GDPR, you have the following rights regarding personal data:

Right of Access: Request a copy of any personal data we hold about you.
Right to Rectification: Request correction of inaccurate or incomplete data.
Right to Erasure (“Right to be Forgotten”): Request deletion of your personal data.
Right to Restrict Processing: Request limits on how we use your data.
Right to Object: Object to our processing based on legitimate interests.
Right to Data Portability: Request transfer of your data in a structured, machine-readable format.

To exercise any of these rights, please email us at privacy@compoundinterestcalculatoruk.co.uk. We respond within one calendar month at zero charge.

6. Right to Lodge a Complaint with the ICO

If you are not satisfied with our response or believe our processing does not comply with UK data protection laws, you have the right to lodge a complaint with the UK supervisory authority:

Information Commissioner’s Office (ICO)

Wycliffe House, Water Lane, Wilmslow, Cheshire, SK9 5AF

Website: ico.org.uk • Helpline: 0303 123 1113

7. Contacting Our Data Privacy Team

If you have questions about this policy or our data practices, contact us via email at privacy@compoundinterestcalculatoruk.co.uk or via our Contact Us page.