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Privacy Policy

Last updated 13 October 2026

Cereal is a live, two-person voice translator for iPhone. This policy explains what personal data we collect when you use the Cereal app and this website, why we collect it, and the rights you have over it.

Cereal is operated by Lettermark Partners Limited (“Cereal”, “we”, “us”), a company registered in England and Wales with company number 13709140 and registered office at 29 D’Arblay Street, London, W1F 8EP. We are the data controller responsible for your personal data and we are registered with the Information Commissioner’s Office (ICO).

The short version

Your conversations are private. When you use Cereal, your device connects directly to our translation provider to turn speech into translated speech. That audio does not pass through Cereal’s own servers, and we do not record, store, or keep a copy of your conversations or their transcripts. What we do handle is the small amount of information needed to give you access, run your subscription, and keep the service secure.

What we collect

  • Account and access data. An identifier for your app installation and your App Store purchase and subscription status, so we can grant you access and manage your plan. If you choose to sign in, so that you can use your account on another iPhone, we also keep your email address and how you signed in: with Apple, with Google, or with a sign-in link sent to your email address. If you sign in with Apple or Google, we also keep your name as that service shares it with us. Apple shares it only the first time you sign in, and only the name you choose to share. We keep it with your account so we can recognise you if you contact us for help. The app does not show it yet. We plan to use it later to address you by name in the app and in our emails, and we will update this policy before we do.
  • Device checks. When you first open the app, it uses Apple’s App Attest and DeviceCheck services to confirm that it is a genuine copy of Cereal on a real iPhone, and to note whether that iPhone has already used its free trial. We keep an identifier for your device’s key and that free-trial status, not anything that names you. To help detect fraud, we also keep the network part of the IP address your device last connected from (its first three numbers), not your full address.
  • Usage metering. The number of minutes of translation you use, together with timestamps and coarse technical logs. We need this to meter usage for billing, manage cost, and prevent abuse. We also combine these records with your purchases into internal business figures, such as minutes used per conversation, passes bought, and how often people run out of minutes, to understand how Cereal is used and improve it. We do this ourselves, without any third-party analytics service, and only we can see it.
  • Service diagnostics. Technical details of your translation sessions, such as the processing counts our translation provider reports during each session, and error and event records our servers keep, some of them linked to your account, so we can run, bill, secure, and support the service. These never include the content of your conversations.
  • Crash and performance reports. If the app crashes or runs slowly, iOS produces a technical report about it through Apple’s MetricKit, and the app sends it to us with the app version and build, your iOS version, and your iPhone model. A report describes what the app was doing, such as the code it was running when it crashed, and never the content of your conversations. The app removes your region setting, the specific values filled into error messages, memory addresses, the process number, and the identifier of the app’s own installation before it sends a report, and our servers remove them again before storing it. We do not attach your account, a device identifier, or your IP address, so reports are not linked to you. We use them only to find and fix problems, and delete them after 90 days. To stop this reporting being abused, we count reports from each network using a scrambled (hashed) form of the network part of the sender’s IP address, and delete those counts within about a day.
  • Support enquiries. If you email us, we keep your message, your contact details, and anything you attach, so we can reply and help. That can include a conversation log you choose to share from the app’s Settings. Conversation logging is off unless you turn it on. Conversation logs never leave your iPhone unless you send one, and stay on it until you delete them, even after you turn logging off. A conversation log records only timing and volume measurements, connection and error events, the audio devices in use (including your AirPods’ name as set on your iPhone), how many characters each transcript had, the app version, your device type and iOS version, the translation mode, and the languages you chose, never what was said. Separately, the app always keeps a small technical log on your iPhone of billing events, connection checks, and basic app health (counts of crashes and other problems from Apple’s reports, your audio set-up when the app opens, and the address of any link it didn’t recognise), with shortened identifiers and nothing you said. It never leaves your iPhone and isn’t included in backups or crash reports. You can’t turn it off or clear it, but it keeps only its most recent entries, about 1 MB, and is deleted when you delete the app.
  • Waitlist sign-ups. If you join the waitlist on this website, we collect your email address, the phone you tell us you use (iPhone or Android), the kind of device you signed up from, and when you joined. We use these details to confirm that you’ve joined, to tell you when Cereal launches, to send you occasional news about Cereal, and to understand how many people want Cereal on each platform. To stop abuse of the sign-up form, we also use your IP address, which we keep only in a scrambled (hashed) form and delete within 24 hours.

What we do not collect

We do not receive, listen to, record, or store the audio of your conversations or their transcripts. Because translation happens directly between your device and our translation provider, that content never reaches our servers. This website does not use advertising or tracking cookies and does not profile visitors, the app contains no third-party analytics or advertising code, and our emails do not contain tracking pixels or tracked links.

Who we share data with

We rely on a small number of trusted providers who process data on our behalf or as independent controllers:

  • OpenAI provides the speech translation. Your audio is sent directly from your device to OpenAI to be translated. OpenAI processes this data under its API terms, does not use API data to train its models by default, and retains it only for a limited period for abuse monitoring. So that OpenAI can apply its abuse protections, each session also includes a scrambled (hashed) identifier for your device or account, which contains no name or email address. The app also checks that OpenAI’s service can be reached from your current network when you open it, when you come back to it, when your network changes, before each conversation and each purchase, and when you tap “Try again”. This check sends no audio, account details, or identifier, and sends or keeps no cookies, but like any internet request it shows OpenAI your device’s IP address, your language settings, and basic technical details of the app and of iOS. See the OpenAI Privacy Policy.
  • Apple distributes the app and handles all payments and subscriptions through the App Store. We receive confirmation of your purchase and entitlement, not your payment card details. Apple also provides Sign in with Apple, if you choose it, which shares your email address with us (or a private relay address, if you hide yours) and, the first time you sign in, the name you choose to share. Apple also runs the device checks described above, and produces the crash and performance reports. See the Apple Privacy Policy.
  • Google confirms who you are if you choose Sign in with Google, and shares your name, email address, and basic profile with us. See the Google Privacy Policy.
  • Cloudflare runs Turnstile, a check that the app is being used by a person rather than an automated script, when the app first connects to our service. Cloudflare processes limited technical signals from your device, such as its IP address, only for that purpose. See the Turnstile Privacy Addendum.
  • Vercel hosts this website, as our processor. When you visit it or join the waitlist, Vercel handles your request, including your IP address and browser details, passes waitlist sign-ups on to our backend, and keeps request logs for a limited period. See the Vercel Privacy Policy.
  • Supabase hosts the backend that issues your access credentials and stores your account details, usage metering, crash and performance reports, and the waitlist, as our processor. Supabase also keeps its own platform and request logs, including IP addresses, for a limited period.
  • Resend sends our emails, including waitlist updates and news about Cereal, and stores your email address and waitlist details for that purpose, as our processor. See the Resend Privacy Policy.
  • Legal and safety. We may disclose information where we are legally required to, or to protect the rights, property, or safety of Cereal, our users, or others.

Legal bases

Under the UK GDPR we process your data on the following bases: performance of a contract, to provide the app and your subscription; legitimate interests, to secure, meter, and improve the service and prevent abuse; legal obligation, to meet accounting and tax duties; and consent, for waitlist and newsletter emails and wherever else the law requires it. You can withdraw consent at any time, including by using the unsubscribe link in any of our emails.

International transfers

Some of our providers, including OpenAI, Apple, Google, Cloudflare, Vercel, and Resend, process data outside the United Kingdom and the European Economic Area, including in the United States. Where that happens, we rely on appropriate safeguards such as the UK International Data Transfer Agreement or Standard Contractual Clauses.

How long we keep it

We keep account and entitlement data for as long as your account is active and as needed to meet legal and accounting obligations. When you delete your account in the app, we straight away erase your name and sign-in details, and keep your email address only in a scrambled (hashed) form. We keep the records of what you bought and the minutes you used, under an account number that contains no name or email address, as long as we need them for accounting and refunds. We also keep a scrambled (keyed hash) form of your email address or sign-in account, so that the free trial cannot be claimed again. Crash and performance reports are deleted after 90 days. Device-check records are deleted after 14 days, records of rate-limit incidents after 7 days, and our servers’ other error and event records after 90 days. Records that an account was deleted, and notices Apple sends us about Sign in with Apple accounts, are kept as audit records for as long as we need them for legal and accounting purposes. Supabase keeps its own platform and request logs for a limited period. Support emails are kept for as long as needed to handle your enquiry. We keep your waitlist details until you ask us to delete them. If you unsubscribe, we stop emailing you, and we only start again if you join the waitlist again.

Your rights

You have the right to access, correct, delete, restrict, or object to the processing of your personal data, to data portability, and to withdraw consent. You can delete your account and its data at any time from the Account screen in the app. To exercise any of these rights, email [email protected]. You can also complain to the ICO at ico.org.uk if you are unhappy with how we have handled your data.

Children

Cereal is not directed at children under 13, and we do not knowingly collect their personal data. If you believe a child has provided us with personal data, please contact us so we can remove it.

Security

We use reasonable technical and organisational measures to protect your data. No method of transmission or storage is completely secure, but the design of Cereal keeps your conversation content off our systems entirely.

Changes to this policy

We may update this policy from time to time. When we do, we will revise the date at the top of this page.

Contact us

Email [email protected], or write to Lettermark Partners Limited, 29 D’Arblay Street, London, W1F 8EP.