Privacy Policy

Last updated: November 3, 2026

1. Who we are

Incredible Letters (incredibleletters.com) is run by Think On Labs LLC ("we", "us"). It helps you write a heartfelt letter to someone you love, then download it, print it, or have us mail it. This policy explains what we collect, why, who else sees it, and how long we keep it.

Our rule is to keep as little as the service needs. A letter is something private between you and the person you write to, and we treat it that way.

2. The short version

  • You can write a letter without an account. If you do, the details you type go to our AI writing helpers to draft it, and the letter stays in your browser. We don't store either.
  • If you sign in and press Save, we store that letter encrypted, and you can delete it, or your whole account, at any time.
  • The AI services that help write your letter never train their models on it, and keep it only briefly, if at all (see section 4).
  • We keep and read the letters you write to improve the site only if you turn on "Help improve Incredible Letters", which is off unless you choose it (section 3.11), or if you send one to us yourself in a feedback report (section 3.12) or after our checks stop it (section 3.13).
  • A mailing address you give us is stored encrypted and shared only with our print-and-mail partner and the address-checking service.
  • We never sell your information, and ad companies never see your letters or the pages where you write them. We never tell a sender whether their letter was opened or delivered.
  • Anyone can ask us to stop sending them letters or emails at incredibleletters.com/stop.

3. What we collect and why

3.1 Writing a letter without an account

To write a letter you tell us about the person you're writing to, such as their first name, age, interests and what makes them special, and you pick a style. We send those details to our AI writing helpers (section 4) to draft the letter, and the letter comes back to your browser. The letter and the details are kept in your browser tab, not on our servers. Closing the tab clears them.

For each letter written we record a few facts with no letter text or details about the recipient in them: the occasion and style chosen, which AI model wrote it, how long it took, and the scores from our safety checks. If you are signed in, these records are linked to your account. If you ask for a different version, we record the reasons you tapped (for example "too long"). The optional note you can type with that request is passed to the AI helpers but never saved, unless you send it to us after our checks stop it (section 3.13).

3.2 Accounts and sign-in

You need an account to save letters, pay, have a letter mailed, or write more than a few letters. You can sign in with a link we email you (no password) or with an account you already have, such as Google. For your account we keep your name if you give it, your email address, what you have unlocked, which version of our terms you agreed to and when, whether you turned "Help improve" on or off and when (section 3.11), and for each signed-in session the IP address and browser it came from. If you sign in with another provider, it tells us your name, email address and profile picture, and we keep the sign-in details it issues. We don't get your password or your contacts.

When you ask for a sign-in link, we keep the address and a scrambled copy of the link (never the link itself) until it's used or expires. Links expire after 15 minutes, and expired ones are cleared within a day.

3.3 Saved letters

A letter is saved only when you are signed in and press Save. We encrypt the letter, its name, the details used to write it and its design with a key held by our application, on top of the encryption our database provider already applies. Someone looking at the database directly would see only scrambled data. You can rename or delete any saved letter on My letters.

Letters for Later. If you schedule saved letters to be emailed on future dates, we also keep, encrypted the same way, the series' name, who it is for, the name you sign the emails with, the email address that receives them, and each letter's date and label. We email that address once to ask whether they want the letters, and send nothing more unless they say yes. A few days before each letter they get a short heads-up. On the day, the email shows who it is from and the opening of the letter (a very short letter shows whole), with a private link that opens the letter on our site (if we have letter links switched off, the email carries the whole letter instead). We keep an encrypted copy of that letter for the link for one year, or less if it is reported or you delete your account, then delete it; deleting the series doesn't take back a letter already sent. Each email has a link to stop the series. Letters can be dated up to 30 years ahead, and we keep the series until you delete it or your account. Before each letter is sent we run the same safety check as when it was written.

If you send a letter as a link, we keep an encrypted copy of it (the words, its design, and the two names on it) so whoever has the link can open it. Only people with the link can open it. We don't email the person you send it to. We keep no record of whether a particular letter was opened, so we can't tell you whether it was read; our own analytics (section 3.10) count openings only as a total across all letters. The link ends after 90 days, or sooner if you switch it off on My letters, and then the copy is deleted. Whoever opens the letter can report it, which switches the link off for everyone; a reported copy is kept 30 days so we can look into it, then deleted.

3.4 Photos

If you add a photo to a letter you download or print yourself, the photo stays in your browser and is never uploaded to us. If we later offer photos in mailed letters, we will explain here how they are handled before that starts.

3.5 Payments

Downloadable letters are pay what you want, and mailed letters have a set price. What you unlock is recorded on your account, and it stays with that account for as long as the account exists. Paying to mail a letter while you are signed in also unlocks the first level of designs on that account.

Payments are handled by Stripe. You enter your card details on Stripe's checkout page, and we never see or store your card number. Stripe processes the card and keeps the payment data under its own privacy policy. When you pay to unlock designs, we pass Stripe the email address of your account so it can send your receipt. When you pay to mail a letter, you type your email address into Stripe's checkout page yourself, and we don't pass it.

For each payment we keep the amount and currency, what it unlocked (or, for a letter pack, how many letters it bought), Stripe's reference numbers for it, the date and time, and whether it has since been refunded or disputed with your bank (a chargeback). A refund or a chargeback takes that money back out of what counts toward your unlock, and if that leaves too little, the unlock ends. While a chargeback is open, that payment doesn't count; if it is decided in our favor, it counts again.

3.6 Mailed letters

If you pay us to mail a letter, we need the recipient's name and mailing address, your name and the letter itself. We check the address with an address-verification service, then send the address, the name you chose for the envelope and a link to the printable letter to our print-and-mail partner, which prints it and posts it. The link expires after 7 days.

The envelope shows the name you choose for it, above "c/o Incredible Letters" and our return address, so the recipient knows who it's from. If you leave it blank, or if we ever have to switch this off, it shows only our name and return address. We never print your own address. Letters the postal service can't deliver come back to us: we destroy them and don't pass on anything written on them, such as a forwarding address.

We keep the address and letter encrypted until 30 days after the letter is printed (or delete them right away if the order is refunded). After that we keep an order record: its status, amount and dates, the recipient's name, a keyed fingerprint of the address (used to limit how many letters one address receives), the print partner's and Stripe's reference numbers, the account that placed it, and which version of our terms the sender agreed to.

To learn how long mail takes, so we can tell people the last day to order for a holiday, we also note when our print partner reports the letter printed, handed to the postal service and delivered or returned, along with the first three digits of the recipient's ZIP code, and delete it about 13 months after the letter is sent. That is for our own planning only. We never tell the sender whether the letter arrived or was opened: the order page shows only our own progress (paid, sent to print, refunded).

3.7 Emails

We send email through Resend. Sign-in links and receipts are sent because you asked for them. If you sign up for our newsletter, tick the box to hear from us, or ask for occasion reminders (for example, the last day to mail a letter in time for a holiday), we send those too, and we keep a record of that choice. We keep open and click tracking off on our emails. If you write to us through the contact form, we receive your name, email address and message so we can reply.

Every email has a link to stop all email from us. That puts your address on our do-not-contact list (section 3.8), so you will also stop getting sign-in links and receipts. You can still sign in with another provider, such as Google.

3.8 The do-not-contact list

Anyone, including someone who received a letter, can ask us never to mail or email them at incredibleletters.com/stop, and every mailed letter and email from us says how. We store each opted-out email or address only as a keyed fingerprint, not the address itself, so we can recognize it later without keeping a readable list. We never tell a sender that someone opted out.

3.9 Keeping the service safe

To stop abuse we count requests by IP address (or by account when signed in), and the counts expire after a day. Some forms use Cloudflare Turnstile, which checks that a person, not a bot, is using the page. Turnstile receives your IP address and browser signals under Cloudflare's privacy policy. We keep hourly counts of letters written and failures, with no details, to watch the site's health.

Our logs never contain the details you typed, the letter text, or the note on a rewrite request.

3.10 Our own analytics

We want to know which pages, posts and ads bring people here and whether the site works for them. For that we use:

  • Vercel Web Analytics and Speed Insights, which count page visits and measure how fast pages load without an analytics cookie.
  • Our own first-party analytics. A cookie with a random id (or your account, when signed in) links steps such as "started a letter", "downloaded", "contributed" and "ordered mail", along with the campaign tags or ad click id on the link that brought you, and which version of a page you saw when we test two. These records never include names, letter text, the details you typed or addresses. They stay with us, except the purchase report described in section 7.
  • Counts of which letter looks were shown, picked, downloaded, mailed and bought, by day and occasion, with no id attached, so the looks people like most come first.

3.11 Help improve Incredible Letters (optional)

This is off unless you turn it on, and it is separate from agreeing to our terms. You can turn it on when you first agree to the terms or on the Account page, and turn it off there at any time.

While it is on, we keep each letter you write while signed in, including attempts our safety checks stopped, as our AI writing helper drafted it, with the details you typed for it (but not the note you can add when asking for a different letter), and we can read the letters you save or change on your account. A person at Incredible Letters may read them in full, including any names in them. We use them to make our letters better, for example to test our letter writing or to train an AI model of our own. We keep them encrypted, never publish them and never sell them.

Turning it off deletes the letters we kept for it. Deleting your account does too, and either way we delete each one a year after we kept it. Your saved letters stay yours as before; we just stop reading them. We record each time you turn it on or off, with the wording you saw, as the record of your choice, and keep that record until you delete your account.

3.12 Feedback reports

While we are testing the site, the footer has a "Send feedback" button for telling us about something that isn't working or an idea to make it better. Before anything is sent you see a list of what the report holds, and you can open each part to see exactly what is in it. You can leave out the recent steps, the picture of the page and your account. Nothing is sent until you press Send.

A report can include:

  • what you wrote, and whether it is a problem or an idea;
  • the page you were on (its address without the part after the "?", and with the secret part of a gift, letter or mail order link taken out), the site's version, and your browser, screen size, language and time zone;
  • the last few things you did in that browser tab: pages you opened, the labels of buttons and links you pressed, errors the page ran into, and requests to our site that failed. We leave out what you typed and anything pressed inside the letter, and on parts of the site that show names or letter titles we leave out the labels. You can see every step before you send it. Until you send a report this list stays in your browser (section 8), and it is cleared when you close the tab;
  • a picture of the page, which shows whatever was on it, including a letter and the names in it;
  • if you are signed in, your account, so we can reply.

We keep each report encrypted, read it only to fix and improve the site, and email ourselves a note that one arrived (the note says only whether it is a problem or an idea). We delete reports after 180 days, and deleting your account deletes the reports you sent with it attached.

3.13 Stopped letters you send us

If our safety checks stop a letter, you can press "Send this to the developer". Only then do we keep a copy of what you typed for that letter (including any note you added and the details about the person you were writing to), why it was stopped, and any draft our AI writing helper wrote before it was stopped. We use it only to find out why the letter was stopped and fix our checks. It is kept encrypted, only people at Incredible Letters can read it, and we delete it after 90 days, or sooner when you delete your account if you were signed in. You can send one without an account; it is then not linked to anyone. If you turned on "Help improve" (section 3.11), stopped letters are already kept under that choice.

4. AI writing helpers

Your letter is drafted and checked by AI models from providers such as Anthropic, reached directly or through Vercel's AI Gateway. We only use providers whose terms say they don't train their models on what we send them. Some keep requests for up to about 30 days to check for abuse and then delete them. A provider may keep something longer if its safety systems flag it. Where keeping nothing at all is available to us at no extra cost, we ask for it.

We also use OpenAI's moderation service to screen the details you type, the finished letter, and any letter before it is mailed. OpenAI states that this service is not used for training and its data is not kept for abuse monitoring.

You are the author of your letter. The AI is a writing helper, and you can edit everything it suggests.

5. Who else sees your information

We share information only with the service providers that run parts of Incredible Letters for us, and only what each one needs:

  • Vercel: hosts the site, runs the AI Gateway and provides traffic analytics.
  • AI providers such as Anthropic (directly or through Vercel): draft and check letters, under terms that rule out training on them.
  • OpenAI: safety screening (moderation).
  • Neon: our database (accounts, encrypted saved letters, encrypted mail orders, the do-not-contact list).
  • Upstash: short-lived request counters and health counts.
  • Stripe: payments, receipts, refunds and chargebacks.
  • thanks.io and any other print-and-mail partner we add: print and mail letters.
  • Lob: checks that a mailing address is deliverable. We use it for nothing else.
  • Resend: sends our emails.
  • Google: sign-in, if you choose it.
  • Cloudflare: the Turnstile bot check.
  • Ad platforms such as Meta and Google: page views on landing pages and purchase reports, as limited in section 7, unless you opt out.

We may also disclose information when the law requires it, for example in response to a valid court order, or to protect someone from harm. If Incredible Letters is ever sold or merged, your information would move with it, and this policy would still apply to it.

6. What we never do

  • Sell your personal information or your letters.
  • Use your letters, or the details you type, to train AI models, unless you turn on "Help improve Incredible Letters" (section 3.11).
  • Tell a sender whether a letter or email was delivered, opened or read, or pass on a recipient's IP address.
  • Put ad tracking on the pages where you write, pay for or mail a letter.
  • Show ads to people because they wrote a letter, or target ads at children.
  • Give a mailing address to anyone except our print-and-mail and address-checking partners.

7. Advertising

We advertise on platforms such as Meta (Facebook and Instagram) and Google so more people find us. To see which ads work, we keep to these limits:

  • Ad platform tags may run on our home page and holiday and occasion landing pages, where they record a page view. They never run on the pages where you write, save, pay for or mail a letter, on your account pages, or on pages for sensitive occasions such as get well, sympathy or hard times.
  • When you pay, our server tells the ad platform that brought you that a purchase happened, with its value, time, the ad's click id and a payment reference so it isn't counted twice. It never sends your name, your letter, or who it was for. We send a hashed email address for better matching only if you tick a box agreeing to it.
  • We don't build ad audiences from the people who write letters, don't retarget you because you wrote one, and don't aim ads at children.

Some state laws, including California's, may treat this ad measurement as "sharing" personal information. You can opt out with the Your Privacy Choices link at the bottom of every page, and we treat a Global Privacy Control signal from your browser as an opt-out. Once you opt out, ad tags don't load for you and we don't report your purchases to anyone.

8. Cookies and browser storage

  • Sign-in cookie: keeps you signed in. It is set only when you sign in and removed when you sign out.
  • Analytics cookie: our own random id, described in section 3.10. It lasts a year and isn't shared with anyone.
  • Page test cookie: when we test two versions of a page (section 3.10), it remembers which one you saw so the page stays the same for you. It lasts a year and isn't shared with anyone.
  • Ad platform cookies: set by Meta, Google and similar tags on landing pages only (section 7), and not at all if you opt out.
  • Browser storage: holds your letter and its details in this tab while you work on it. It is cleared when you close the tab or sign out. While the feedback button is on, it also holds the list of your last few steps in the tab (section 3.12), which is cleared when you close the tab and sent only in a report you choose to send.

You can block cookies in your browser, but then you won't be able to sign in or check out.

9. How long we keep things

  • Letters written without an account: never stored by us.
  • Saved letters: until you delete them or your account.
  • Letters kept with "Help improve" on: until you turn it off or delete your account, and never more than a year.
  • Letters sent as a link: until the link ends (90 days) or you switch it off, then deleted within a day. Reported ones: 30 days.
  • Letters for Later series: until you delete the series or your account. Letters can be dated at most 30 years ahead. The copy behind each emailed letter's link: one year after it is sent.
  • Your account: until you delete it. Deleting it removes your saved letters, your sessions, the records of letters you wrote, any letters kept with "Help improve" on and the record of that choice, the feedback reports and stopped letters it sent, and what you unlocked. Records of paid mail orders (below) are business records and stay after the account is gone.
  • Feedback reports: 180 days, or until you delete the account that sent them.
  • Stopped letters you choose to send (section 3.13): 90 days, or until you delete the account that sent them.
  • Sign-in links: at most about a day.
  • Mailing addresses and mailed letters: 30 days after printing, or until a refund. The order's status, the recipient's name and the payment references are kept as business records.
  • Request counters: one day.
  • Analytics records: kept as they were recorded for 90 days, then only as daily totals by source and campaign, to compare campaigns and seasons from year to year. Never with letter content. Deleting your account takes your account off them.
  • Do-not-contact fingerprints: kept so we can keep honoring the request.
  • Payment records: Stripe keeps them under its own policy. We keep the amount, currency, what it unlocked, the reference numbers, the dates and any refund or chargeback as our business records. When you delete your account they stay, no longer linked to your account here (Stripe keeps its own records under its policy).

10. Children

Incredible Letters is for adults writing to people they care about, often children. Children should not use it themselves, and we don't knowingly collect personal information from anyone under 13. The details an adult types about a child are used to draft the letter and are stored only if the adult saves or mails it, or has turned on "Help improve" (section 3.11). A parent or guardian can put a child's mailing address or email on our do-not-contact list at incredibleletters.com/stop. If you think a child has given us personal information, contact us and we will delete it.

11. Your choices and rights

  • Delete a saved letter on My letters, or your whole account on the Account page. Both take effect right away.
  • Turn "Help improve Incredible Letters" on or off on the Account page. Turning it off deletes the letters kept for it.
  • Stop all email from us with the link in any of them. This also stops sign-in links to that address.
  • Opt out of ad measurement with Your Privacy Choices or your browser's Global Privacy Control setting.
  • Stop all letters and emails from us at incredibleletters.com/stop.
  • Ask us what we hold about you, or ask us to correct or delete it, by emailing us (section 14). Depending on where you live, for example California or the European Union, you may have further rights under local law, and we won't treat you differently for using them.

12. Security

Saved letters, and the letter and address in a mail order, are encrypted by our application, all traffic uses HTTPS, and access to our systems is limited. No system is perfectly secure, so we keep only what we need. If a breach ever affects your information, we will tell you as the law requires.

13. Changes to this policy

When we change this policy we update the date at the top. If a change matters to how we use information you have already given us, we will tell you by email or on the site before it takes effect.

14. Contact us

Questions or requests about your privacy:

Think On Labs LLC
Email: privacy@thinkonlabs.com