Privacy policy

Last updated: 27 September 2026.

Account sign-in is switched off at the moment — there is currently no way to create an account or save a calculation on this site, and we are not collecting any email addresses. The calculator itself still works with no data sent anywhere. Section 2 below describes how the account feature will work once it is switched back on.

Who we are

Overpay or Invest (https://overpayorinvest.com) is run by an individual based in Australia and is aimed at readers in the United Kingdom. We handle personal data in line with UK data protection law, and we are the controller of any personal data described in this policy. Contact: hello@overpayorinvest.com.

The short version

• You don’t need an account to use the calculator. The figures you enter stay in your browser and are not sent to us, unless you choose to save a calculation.
• Creating an account is optional, and needs only an email address — no password. We use it to sign you in and to store any calculations you choose to save.
• Signing in sets one cookie, needed to keep you signed in. We don’t use it, or any other cookie, to track you.
• We use privacy-friendly analytics to count visits.
• We don’t currently show advertising. If we ever do, we will update this policy and ask for your consent first.

What we collect and why

1. Your calculator inputs, if you don’t sign in

Your loan balance, salary and plan type are processed by code running in your own browser to produce the result on screen. They are not transmitted to us or to any third party, and they are gone when you close or refresh the page.

2. Your account, if you choose to sign in

If you sign in, we store your email address, and, for each calculation you save, the figures you entered and the result shown at the time. We use this only to show your saved calculations back to you and let you track them over time. Our lawful basis is your consent: signing in and choosing to save a calculation is an active choice, and you can delete any saved calculation, or your whole account, at any time from your account page or by emailing us.

Signing in works by emailing you a one-time link, rather than a password. We keep a temporary record of that link (as a scrambled, one-way hash, not the link itself) for 15 minutes so we can verify it, then it expires or is deleted once used.

3. Technical and analytics data

Our site is hosted and delivered by Cloudflare. To serve pages and keep the site secure, Cloudflare processes technical data such as your IP address, browser type and the page requested. We also use Cloudflare Web Analytics to see aggregate statistics such as page views, referrers, countries and device types. Cloudflare states that Web Analytics does not use cookies or track individuals across sites. Our lawful basis is legitimate interests: running, securing and improving the site.

4. Emails you send us, or that we send you

If you email us, we use your email address and message to reply and to keep a record of the conversation. If you sign in, we send a one-time sign-in link to the email address you provide, via Resend, our email-sending provider. Our lawful basis is legitimate interests (or taking steps at your request). We keep support emails for as long as needed to deal with your query, and normally no longer than two years.

Cookies

See our cookie policy.

Who we share data with

We share technical data with Cloudflare, Inc., as our hosting, security, database and analytics provider, and, only if you sign in, your email address with Resend, our email-sending provider, solely to deliver your sign-in link. We do not sell personal data. Both are based in, or process data in, the United States, so data may be transferred outside the UK. Both rely on recognised safeguards for such transfers; see their own privacy documentation for details.

Your rights

Under UK data protection law you have the right to ask for access to your personal data, to have it corrected or deleted, to restrict or object to our use of it and, in some cases, to receive a copy in a portable format. If you have an account, you can delete individual saved calculations yourself at any time; email us to delete your account entirely or to exercise any other right. There is no charge, and we will respond within one month.

If you are unhappy with how we handle your data, you can complain to the Information Commissioner’s Office (ICO) at ico.org.uk/make-a-complaint. We would appreciate the chance to put things right first.

Children

This site is intended for adults and is not aimed at children.

Changes to this policy

If we change how we handle data, for example by adding advertising, we will update this page and the date at the top before the change takes effect.