Sub-processors
Last updated: 28 October 2026. TowerTalk is a trading name of TowerTalk Ltd, a company registered in England and Wales (company number 17318142).
Who handles data for us
These are the companies that handle personal data for TowerTalk in order to run the service. They act on our instructions and under their own terms with us. This table matches the list in our privacy policy, which also explains the safeguards used when data leaves the UK and what each company receives. We do not sell your data.
| Provider | What it does for us | Data involved | Where it operates | Last updated |
|---|---|---|---|---|
| Supabase | Our database, file storage and sign-in. | Everything stored for your account: profile, training history and transcripts, school records, uploaded files, our own usage counts, consent and email records. | Cloud infrastructure in the region of our Supabase project. May involve processing outside the UK; see the privacy policy. | 28 October 2026 |
| Vercel | Hosting and delivery of the website, app and server functions. | Requests to our site, including IP address and country; server logs; data passing through our server functions, including transcripts. | United States / global. | 28 October 2026 |
| OpenAI | Transcribing your spoken calls; writing the controller’s replies and marking; checking input for harmful content; the controller’s spoken voice; the help assistant. | Audio of your calls while it is transcribed; transcripts and context such as callsign, aircraft type and airfield; the controller’s text for speech; help-assistant messages. | United States / global. | 28 October 2026 |
| Anthropic | Reviewing the controller’s draft reply; marking; answering instead if OpenAI is unavailable. | Transcripts and the controller conversation, with context such as callsign, aircraft type and airfield. No audio. | United States / global. | 28 October 2026 |
| Stripe | Taking payment and managing subscriptions. | Your name, email address and plan when you check out; your payment details, which go to Stripe and never to us; subscription and pass status sent back to us. | United States / global. | 28 October 2026 |
| Resend | Sending service and (with your consent) marketing email. | Your email address, the content of the emails we send you, and delivery events. | United States / global. | 28 October 2026 |
| Daily | Live video and audio for lesson rooms and voice rooms. | Live audio and video of the rooms you join, and room names. TowerTalk does not record lessons. | United States / global. | 28 October 2026 |
| Cloudflare (Turnstile) | The sign-up check that you are a person, where it is switched on. | Signals from your browser and connection when the sign-up form loads. | United States / global. | 28 October 2026 |
| Google (Sign in with Google) | Signing in, if you choose it. | Your Google identity and email address. | United States / global. | 28 October 2026 |
| Google (Analytics and Ads tag) | Measuring which pages and campaigns help people learn. | Page views, device and browser data, campaign source and cookie identifiers. Loaded only if you allow it in the UK and EEA, and with an opt-out elsewhere. | United States / global. | 28 October 2026 |
| Backup voice services (only if we switch them on) | If our main voice provider is unavailable: a backup transcription server (our own, or a hosted service that follows OpenAI’s interface) and Google Cloud Text-to-Speech for the controller’s voice. | For transcription, the audio of your call; for speech, the controller’s text. Not used unless a backup has been configured. | Depends on the service chosen. | 28 October 2026 |
Not on this list
Some services receive no personal data from us, so they are not sub-processors. For example, weather and place-name lookups receive only airfield codes or coordinates. Your school or instructor may also connect its own systems to TowerTalk (for example a training-management system); those are the school’s own suppliers, covered in the “If you train with a school or tutor” section of the privacy policy.
Changes and questions
We update this page when we add or change a provider, with the date above. For questions, email info@towertalk.co.uk. Security is covered on our security page.