Privacy notice

Who we are

WindowSim is a trading name of Bond Labs Limited. windowsim.com Company number 17285766. Registered in England and Wales. Registered office: 71-75 Shelton Street, Covent Garden, London, WC2H 9JQ. ICO registration ZC188014.

Bond Labs Limited is the data controller for personal data that reaches us, such as a support message or a Plus billing profile. Drafts and photos that only live on your device stay on your device unless you tap Read the photos, send a support message, start Plus, or choose an optional cloud backup. ICO registration is a fee listing, not a badge and not ICO-approved.

What we hold

Drafts, photos, your firm lines, the rate book, and device preferences are stored on this device in IndexedDB. Saving a draft on this device does not send that draft to a WindowSim server.

When you tap Read the photos, those photos and your notes are sent to xAI so the app can draft openings. The result is stored on this device. AI requests require a verified account and use a daily allowance.

When you tap Show the picked spec on this photo, the on-site photo and the painted mask are sent to xAI to change the frames inside the paint. Brick outside the paint is put back from the original photo. If XAI_API_KEY is missing, nothing is sent.

If you send a message from Contact, that message is emailed through Resend to support@windowsim.com. You may also write to hello@windowsim.com. The message is what you typed, plus optional name and email if you entered them.

Optional accounts email you a six-digit code to confirm the address is yours. Choosing Back up this device uploads jobs, photos, internal notes, company details and rates as a separate copy for your firm. Signing in does not upload or merge local work. We do not sell personal data. If you install the app, the phone may keep a copy of the app files so the desk still opens with no signal. We do not set advertising cookies.

Plus, payments, and stores

Plus is an optional monthly subscription. The published price is £14.99 a month including VAT. It renews until you cancel. Plus is not live. No card is taken. Subscribe stays off until we turn payments on.

On the web app, Stripe Checkout and the Stripe customer portal process the payment. Stripe holds the card. We store a user UUID, a Stripe customer id, and a subscription expiry written only by the Stripe webhook. The app never writes that expiry itself.

On iPhone and Android, Plus is an in-app purchase through Apple or Google, using RevenueCat. Apple or Google hold the store account. We store a user UUID and a subscription expiry written only by the RevenueCat webhook. Restore purchases asks the store. Cancel from Apple or Google subscriptions, not from a web checkout.

A native app does not send you to Stripe Checkout. A web subscription is not an App Store or Play purchase. We do not link a native in-app purchase to a Stripe customer.

Lawful basis

UK GDPR and the Data Protection Act 2018. Providing a feature you tap, such as Read the photos, sending support mail, or starting Plus, is processing at your request to use the app. Support mail is also handled on the legitimate interest of answering the person who wrote to us. On-device IndexedDB stays on this device under your control.

Read the photos sends images to xAI, which is outside the UK. Do not use that control if you cannot send those photos for processing. Support mail is sent through Resend. Stripe, Apple, Google, and RevenueCat process payment data outside this device when Plus is live.

How long we keep it

Drafts and photos stay on this device until you delete a job, wipe this device, or clear this site's data in the browser. Optional cloud backups are separate copies kept until you delete a copy or the cloud account. Backups are manual, not continuous sync. Support mail is kept only as long as needed to deal with the request.

A Plus billing profile (user UUID, subscription expiry, and Stripe customer id if any) is kept while the subscription can still be restored, then deleted or emptied when you use Delete account. Store receipts stay with Apple, Google, or Stripe until you cancel there.

Your rights

You can ask for access, correction, deletion, restriction, or objection, and you can complain to the Information Commissioner's Office at ico.org.uk. Because most data never leaves this device, deleting a draft or wiping this device is the practical way to erase it here. For a message we have already received, write to support@windowsim.com.

Account deletion

Delete account in Settings verifies the signed-in account, revokes its sessions, and removes it and its cloud copies. Local drafts, photos, firm details and rates are kept on this device. Use Wipe device to remove those separately. Account deletion does not cancel Apple, Google, or Stripe by itself. Cancel Plus through the payment provider.

Children

This app is for tradespeople quoting UK windows and doors. It is not for children. It is not directed at children. We do not knowingly collect personal data from children.

Changes

If this notice changes, the new wording will appear on this page. Effective 6 September 2026.

Contact

Write to support@windowsim.com. WindowSim is a trading name of Bond Labs Limited. windowsim.com Company number 17285766. Registered in England and Wales. Registered office: 71-75 Shelton Street, Covent Garden, London, WC2H 9JQ. ICO registration ZC188014.