Privacy

What we keep, and why.

We keep only what the Twin Calendar needs to work, and we never sell it or show you adverts.

Last updated 13 October 2026.

Who we are

Llerrosi & Co is a trading name of Solid Contracts Ltd, which is responsible for your data.

Questions or requests: asorrell@solidcontracts.co.uk.

What we keep

• Your email address, so we can send you a sign-in code. The code itself is stored scrambled and lasts five minutes. If you change your email, we keep a scrambled copy of the old one so it can no longer sign in to your account, and we tell the old address it was changed, with a link that undoes it for 7 days.
• A sign-in record for each device you use: a scrambled copy of the sign-in cookie and the browser's own description of itself, such as its name and version. It lasts a year or until you sign out.
• The dates you add and their notes, encrypted before they are stored. A date read from a photo also keeps the words as they were read off your wall calendar, encrypted, so a later photo still knows it after you rename it.
• Your groups: each group's name, and the email addresses of the people you invite to it. Everyone in a group sees each date, who added it and when. We note when you last opened each group, so we can show what is new to you.
• Your household: up to five email addresses you add so those people can scan their calendar under your Premium, encrypted, with a scrambled copy of each so an account can be matched to its household. Their scans count against your household’s thirty a month, or forty with the add-on.
• Your scans: how many your household used this month and what they cost us to read, and a scrambled fingerprint of each page’s words, so a second photo of an unchanged page is not read again. We can pause scanning for an account that misuses it.
• Find a time: when you offer times to people in a group, we keep the request for seven days: who you asked, the times you offered, and which one was picked. Nobody's calendar is read by anyone but them: the people you ask see only the times you offered, and you see only the one they tap. The link in their email can answer that one request and nothing else. A link you share asks for a first name and the times each person can do, which everyone with the link can see; it is kept with the request for seven days. Someone on that link may photograph their own wall calendar to see which of the times they are free: the photo is read by Google as above and thrown away, nothing it shows is kept, and only they see the answer. Those reads come out of the allowance of the account that shared the link.
• Your scan list: for each photo you send, when, what happened and whether it used a scan, never the photo or its words, kept for this month and the two before and shown to you under Account, Scans. We see it only if you press Share with developer: we then get a copy with your email, kept 30 days or until you stop sharing.
• Your name, if you add it, encrypted, and shown to the people in your groups beside your email.
• Your family’s first names, if you add them, and the repeats you keep or turn down, encrypted. We use them only to spot repeats in your own dates, never to work out anything about you.
• Your paper calendar: which dates are written on it, which you said are not for it, its name if you give one, and whose paper calendar you look at if you choose a family member's. They can see in Account that you look at it too. The code printed on each page is read from your photo, on our own server, to know which paper calendar it is; we keep only a scrambled copy of it, and whose paper calendar it is once the family who activated it says so.
• What you buy here: each purchase's plan, amount, date and Stripe reference, and for a gift its code, encrypted, and the day it was used; the buyer is never told who used it. We keep purchase records for six years for tax, without your name or email, even if you delete your account. Stripe takes the payment; we never see or keep your card details.
• The paper calendars you photograph: the name you give each one, encrypted, and which of your dates came from it, never the photo.
• Your free day: when it started, so we know when it ends.
• After you delete your account: a scrambled copy of your email address, never the address itself, with when your free day began and what this month’s free Premium has used, so they are not given twice.
• Your last change to a date: the date as it was, encrypted, so you can undo it; it is deleted within a day.
• Your school holidays: the council or nation they come from, or your school’s pasted term dates, encrypted. Your postcode finds the council and is not kept.
• Your bin routine: each bin, one collection date and how many weeks apart they come; in a household it is shared with everyone in it, with who gets the reminders and who said the bins were out.
• Your home, for its bin days: if you find your bin days from your council, your postcode, the home you chose and its council, encrypted, and the collection dates your council gives, so we can ask your council each week and remind you on the right day. It is kept on the account of whoever holds the household, or on yours if you said it is your own home, and it goes when the bins are taken off, someone chooses Forget my home, or that account is cleared or deleted.
• Bin day reminders: if you turn them on, the push address your phone gives us, encrypted, so we can send the reminder from 16:00 the day before until the bins are out. Nothing else is sent to it unless you turn on date alerts.
• Date alerts: if you turn them on, each of your dates is sent to your phones an hour or a day before it, through Apple's and Google's push services, encrypted on the way.
• Your printed calendar: when its QR code names one of our ready-printed editions, we note which one, so a photo of it can be read against the right page. Its code, on every page, unlocks the account that scans it first, and we note which account that was.
• Phone calendar links, if you make one: one long secret link for the calendars you tick, kept scrambled to look it up and encrypted so Account can show it again, which you can stop at any time. Anyone holding the link can read those calendars' dates, so keep it to yourself. Someone in your household can send you a group you are both in: the link comes to you by email, with your address kept encrypted beside it so it works before you sign in.
• Your calendar designs: their settings only, including any school term dates you paste in.

We never keep a photo or picture: a photo of your wall calendar is read and discarded, and the designer takes no logo, cover picture or artwork.

A family calendar may hold children's names and birthdays. Only the people in that group can see them.

In Account you can export everything we hold for you as one CSV file, clear your dates, designs and settings while keeping your account and its Premium, or delete the account.

What we count

When someone opens a month page from outside the site, usually by scanning a calendar's QR code, we add one to that day's total.

We also count sign-ins, new accounts and dates added each day. These are totals only: no names, emails or IP addresses are kept with them.

Cookies and your browser

We set one cookie, and only when you sign in: it keeps you signed in. There are no advertising or tracking cookies.

Who helps us run it

• Vercel hosts the site, running it in London. It keeps short technical logs of requests, which include IP addresses.
• Google Cloud Firestore (Firebase) stores the data above, in London.
• Resend sends the sign-in emails.
• Stripe takes payments when you buy Premium here, under its own terms, and is told your email address so it can send your receipt.
• Google Fonts supplies the lettering, so your browser asks Google for it.
• postcodes.io finds your council when you type a postcode into the designer; we keep neither the postcode nor the answer.
• Apple and Google deliver bin day reminders to your phone through their own push services.
• Your council’s website is asked for your bin days when you use Find my bin days, through our own reader on Google Cloud in London. Your postcode and home are passed on when you find your bin days, and each week after, to keep them up to date.
• Google or Apple fetch a calendar's dates through a phone calendar link, if you add one to their calendar app, and keep a copy under their own terms; a group's link shares that group's dates this way, so it is for its members to choose. We note only when a link was last fetched.
• OpenStreetMap draws the map you tap your home on, so your browser asks it for the map pictures.
• Google reads a photo of your wall calendar when you send one: Cloud Vision checks it, and Gemini, which may read it outside the UK, reads the writing. So that it reads only what is new, Gemini is also sent that month’s dates from your calendars and the notes you turned down before. Photos are sent to Google only to be read, and are not kept. Notes you untick after a scan are remembered, encrypted, so they are not offered again.

Some of these companies are based in the United States and handle data under their own data protection terms.

To stop misuse, we count requests for up to a day against a scrambled copy of your email or IP address.

Calendars bought on Amazon

Amazon gives us the delivery name and address so we can post your calendar, and we use them for nothing else.

Why we use it

To give you the service you signed up for, and to keep it secure and working. The daily totals tell us whether people use the digital twin.

How long we keep it

Until you delete your account. Open your month page, choose Account, open Account at the top of its list, then Delete my account.

Deleting removes your email, your dates, your designs and every calendar you own, including family calendars you made. The daily totals stay, as they hold nothing about you.

Your rights

You can ask to see, correct or delete what we hold about you, or object to how we use it. Email us and we will reply within a month.

If you are unhappy with our answer, you can complain to the Information Commissioner's Office.