Privacy policy
Last updated 4 October 2026
Groundproof is run by The 36th Solutions Ltd, a company registered in Nigeria (Abuja, Nigeria). We are the data controller for the information described here. Questions or requests: the36thltd@outlook.com.
What we collect
We collect only what the service needs to work:
- Your email address, to sign you in with a one-time code or link, and to contact you about your account.
- Property details you enter: a name for the property and its NIPOST postcode, plus the address details NIPOST returns for that postcode.
- Check-in photos taken inside the Groundproof app. The app can't upload photos from your gallery.
- Precise location, read only at the moment a check-in photo is taken in the app. We don't track location in the background or at any other time.
- Compass direction and time recorded with each photo.
- Device details: phone make, model and operating system, and whether the app is running on a real phone or an emulator. We use this to detect faked check-ins.
- Payment records: what you bought, the amount and the Paystack transaction reference. Card and bank details are handled by Paystack; we never see or store them.
- Waitlist emails if you join the waitlist on our website.
How we use it
- To check whether each check-in was made at the registered building, using the location, compass direction, device details and photos.
- To show property owners their check-ins, photos and verdicts.
- To take payments and apply what you bought.
- To send sign-in emails and service messages, such as a flagged check-in alert.
We don't sell your data, use it for advertising, or share it with data brokers.
Who can see it
Photos, locations and verdicts for a property are visible only to that property's owner and the people the owner invited to it. We share data with these service providers, only as needed to run Groundproof:
- Supabase: database, sign-in and photo storage.
- Vercel: website hosting.
- NIPOST: postcodes and photo locations are checked against the national postcode registry.
- Anthropic: check-in photos are sent to Anthropic's Claude AI to compare them with the property's earlier photos and describe visible progress.
- Paystack: payment processing.
- Resend: sending emails.
- Expo: building and delivering the mobile app.
Some of these providers process data outside Nigeria and the UK, under their own data protection safeguards.
How long we keep it
We keep your data while your account is open. When you delete your account, we delete your email, your properties, and their photos and check-ins straight away. Check-ins you made on someone else's property stay in their history, no longer linked to you. Paystack keeps payment records as financial law requires.
Your rights
Under the Nigeria Data Protection Act 2023 and, where it applies, UK GDPR, you can ask to see, correct, export or delete your data, and object to how we use it. Email the36thltd@outlook.com. You can delete your account yourself at any time; see Delete your account. You can also complain to the Nigeria Data Protection Commission or, in the UK, the Information Commissioner's Office.
Security
Data is encrypted in transit. Photos are stored privately and shown only through short-lived links to people with access to the property.
Children
Groundproof is not meant for anyone under 18.
Changes
If we change this policy, we'll update the date above and tell account holders about significant changes by email.