Privacy notice

Last updated 2 September 2026

Martian Cow (“we”) sells personalised greeting cards, songs and gifts at martiancow.com. This notice explains what personal data we collect, who we send it to and why. We are the data controller. Contact: hello@martiancow.com.

What we collect

• Your details: email, name and payment details, collected and processed by Stripe at checkout. We never see or store your full card number.
• The recipient's details: their name, delivery address, the message you write inside, and the facts you give us for their song. You provide these about someone else — see “About the recipient” below.
• Photos you upload: if you use the AI design feature, the photo is sent to Google's Gemini model, which draws a stylised likeness for the card front. We do not store the photo itself — only the artwork Gemini draws from it. Google processes it under their own terms.
• Reminder details: who, occasion, date and your email, if you set a birthday reminder.
• Usage data: pages viewed, actions taken, approximate location from your IP, device and browser. With your consent this includes session recordings (see below).

Session recording

If you accept analytics cookies, PostHog records your session on the site — the pages you view and where you click — so we can see where the shop is confusing. Everything you type into a text box is masked before it leaves your browser, so your card message, the facts about the recipient, your email and your phone number are never recorded. Payment details are entered on Stripe's own pages and are never in scope. Recordings are stored in the EU and deleted after 30 days.

Who we share it with

• Stripe — payments and order records, including your order details.
• Vercel — hosting, site analytics, and storage of the AI card designs.
• Google (Gemini) — receives any photo you upload and the text you ask for on the card, plus the facts you write for gift suggestions.
• Our AI music provider — receives only the song brief you write.
• Our UK print and postage partner — receives the card artwork and the delivery address.
• PostHog (EU) — product analytics and session recordings, only with your consent.
• TikTok — only with your consent, to measure our advertising. When you buy something we also send TikTok a server-side record of the purchase containing your email address and phone number in hashed (irreversible) form, your IP address, browser, and the ad click that brought you here. If you choose “Essential only”, none of this is sent.

We do not sell personal data. Some of these providers are in the United States; those transfers rely on the UK International Data Transfer Addendum to the EU Standard Contractual Clauses.

About the recipient

When you order, you give us personal data about someone else: their name, address, your message, facts about them, and sometimes their photo. Please only send a photo of someone who is happy for you to do so, and do not include sensitive information (health, beliefs, sexuality and similar) in the message or song brief. We use the recipient's data only to make and deliver the order. If you are a recipient and want your data removed, email us and we will delete it.

Why we are allowed to use it

• To perform our contract with you — making, printing and delivering your order.
• Your consent — analytics, session recording and advertising cookies. You can withdraw it at any time by clearing the mc_consent cookie in your browser settings.
• Legal obligation — keeping sales records for tax.

How long we keep it

• Order records, held by Stripe: 6 years, for tax. These include the recipient's name, your card message and the facts you wrote for the song, because they are part of the order.
• AI card artwork and song audio: 12 months, then automatically deleted.
• Photos you upload: not stored by us at all (see above).
• Session recordings: 30 days.
• Reminders: until you ask us to delete them.

Your rights

Under UK GDPR you can ask for a copy of your data, ask us to correct or delete it, object to processing, or withdraw consent. Email us and we will respond within one month. If you are unhappy you can complain to the Information Commissioner's Office at ico.org.uk.

Cookies

Essential cookies run the shop and remember your cookie choice and which price you were shown; these are always on. If you press “Accept”, we also set a first-party visitor ID (mc_uid, 12 months) and, if you arrived from a TikTok ad, that ad's click ID (90 days), and we load the TikTok Pixel and PostHog. If you press “Essential only”, none of those are set or loaded. You can change your mind by clearing cookies for this site.