Privacy policy

Last updated 1 October 2026

The short version

We collect only what Kaayi needs to work.
We never sell your data, show you ads, or track you across other apps and websites.
Only you, and the people you choose to share an item with, can see your entries.
You can download a copy of your data or delete your account at any time, from inside Kaayi.

Who we are

Kaayi and this website are run by PARADOX DYNAMICS LTD (“we”, “us”), a company registered in England and Wales, company number 17143231, with its registered office at 6 Whitehey, Skelmersdale, England, WN8 8AQ. We are the controller of the personal data described here.

For anything about your data, email hello@paradoxdynamics.co.uk with “Privacy” in the subject line.

This policy covers Kaayi, on the web and as an iPhone app, and this website (paradoxdynamics.co.uk).

What we collect and why

What	Why	Legal basis
Account details: your name, email address and password. Your password is stored only in scrambled form (a “hash”), so nobody can read it, us included. If you sign in with Google, we receive your name, email address and a link to your Google profile picture, which Kaayi doesn’t use.	To create your account, sign you in, and show your name to people you share with.	Contract
What you enter: debts and who they’re owed to, amounts, interest rates, due dates, payments, income sources and their figures, your budget and plan settings, your currency, and anything else you type in.	To provide Kaayi: balances, plans, reminders and sharing.	Contract
People you invite: their email address and the access you give them. Once they join, the name they signed up with.	To let you share particular items with them.	Legitimate interests (yours, in managing money together)
Activity history: a record of changes to your items (what changed, when, and by whom).	So you and the people you share with can see changes, and restore deleted items.	Contract
Technical and security data: your IP address, browser or device type and sign-in times, recorded by our service providers, and the signals Cloudflare’s robot check uses on the sign-in screen.	To keep accounts secure, stop abuse and fix problems.	Legitimate interests
Messages you send us: your email address and what you write.	To reply and help you.	Legitimate interests

We don’t collect your contacts, location or photos. Kaayi never connects to your bank, and never asks for bank logins or card numbers. We don’t use analytics or advertising tools.

On your iPhone

Reminders are scheduled by your iPhone itself. The reminder text, such as a debt’s name and due date, stays on your phone.
Face ID is handled entirely by iOS. Kaayi only learns whether the check passed. It never sees your face data.
Backups you download are saved wherever you choose. We don’t receive a copy.

Who can see your data

You see everything you enter. People you share with see only the particular debt or income source you shared, with its monthly entries and history, and the name you signed up with.
Us. As with any online service, we can technically reach the database. We only do so to run and fix the service, to help you when you ask, or when the law requires it.
Our service providers, who handle data only on our instructions:
- Supabase, Inc.: Kaayi’s database and sign-in. Your Kaayi data is stored in Ireland (EU).
- Vercel Inc.: hosts the Kaayi web app.
- Cloudflare, Inc.: the robot check on the sign-in screen, our domain, this website and our email.
- Google: sends Kaayi’s sign-in and password emails, provides “Continue with Google” if you choose it, and delivers the typeface used by Kaayi and this website (Google Fonts).
Apple, if you download Kaayi from the App Store, handles that under its own privacy policy.

We’ll only share data otherwise if the law requires it, or to protect someone’s safety. If our company were ever sold or merged, your data would pass to the new owner under this policy, and we’d tell you first. We never sell your data.

Where your data goes

Kaayi’s data is stored in Ireland, which UK law recognises as protecting personal data adequately. Some of our providers are based in the United States and may process data there, for example to keep their services secure. When that happens, we rely on the safeguards UK data protection law requires, such as the UK–US data bridge or the UK’s approved contract clauses.

How long we keep it

Your account and entries: for as long as you have an account.
Items you delete move to “Recently deleted” so you can restore them. They’re erased for good when you delete your account.
When you delete your account, everything you own is erased from our live database straight away. Copies may stay in our hosting provider’s routine backups for a short time, until they’re overwritten. What you recorded on someone else’s item stays with that item, because it’s part of their records.
Security and sign-in logs are kept by our providers for a short time.
Emails to us are kept only as long as we need them to help you.

Your rights

Under UK data protection law, you can ask us to:

give you a copy of your data (you can also use Account → Download a backup at any time);
correct it (most of it you can edit in Kaayi yourself);
delete it (Account → Delete my account, or email us);
restrict or object to how we use it.

Email hello@paradoxdynamics.co.uk. We’ll reply within one month. If you’re unhappy with how we’ve handled your data, please tell us first. You also have the right to complain to the Information Commissioner’s Office (ICO), at ico.org.uk/make-a-complaint or on 0303 123 1113.

Keeping it safe

Everything travels encrypted (HTTPS). Passwords are stored only as hashes. Strict rules in the database mean each item can be seen only by its owner and the people it’s shared with. New accounts must confirm their email address, the sign-in screen has a robot check, and on iPhone you can lock Kaayi with Face ID. No system is perfectly secure. If a breach ever affects your data, we’ll tell you, and the ICO, as the law requires.

Children

Kaayi is meant for adults (18 and over) and isn’t aimed at children. If you think a child has made an account, contact us and we’ll delete it.

Cookies and storage

Neither Kaayi nor this website uses cookies for advertising or analytics. Kaayi’s web app keeps your sign-in in your browser’s storage so you stay signed in; if you untick “Remember me”, only until you close the tab. The iPhone app keeps your Face ID lock setting on your phone. Cloudflare’s robot check may store what it needs to tell people from bots. These are all strictly necessary for the service, so they don’t need your consent.

This website (paradoxdynamics.co.uk) sets no cookies and collects no personal data, beyond the IP address our host (Cloudflare) and Google Fonts see when delivering pages.

Changes to this policy

If we change this policy, we’ll update this page and the date at the top. If a change matters, we’ll also tell you in Kaayi or by email before it takes effect.