Tetra720 Privacy Policy
Last updated: August 11, 2026
This Privacy Policy describes how TETRA720 LLC ("we", "us", "Tetra720") collects, uses, and protects your information when you visit our website, purchase C3, or use C3 on your computer.
We've kept this short on purpose. Please read it.
1. Who we are
TETRA720 LLC is a Limited Liability Company organized under the laws of the State of Illinois, USA. We make and sell C3, a 2D computer-aided design (CAD) application for macOS.
You can reach us at legal@tetra720.com.
2. What we collect
When you visit our website (tetra720.com)
We collect basic technical information your browser sends automatically: IP address, browser type and version, operating system, referring page, and pages you visit. We use this to operate the site, diagnose problems, and protect against abuse.
We also use two measurement tools on our website:
- Vercel Analytics — provided by Vercel, who host our website. It counts visits and page views in aggregate so we know which pages people find useful. It sets no cookies and does not follow you to other websites. To count a repeat visit within a single day it uses a scrambled identifier derived from your browser and connection, which is discarded and regenerated daily and is never used to identify you personally.
- The Meta pixel — a small piece of code from Meta Platforms (Facebook, Instagram) that tells us which of our advertisements brought people to our site and what they did once they arrived. This does mean sharing information about your visit with Meta: your IP address, the pages you view on our site, and whether you submitted one of our forms. If you have a Facebook or Instagram account, Meta may connect that activity to it. We use this only to measure and improve our advertising.
You can opt out of the Meta pixel at any time — see Section 10.
When you buy C3
We accept payment through several channels; the information handled depends on which one you use.
- Credit or debit card — processed by Stripe (our payment processor). Stripe collects and processes your name, email address, billing address, and payment card details. Tetra720 receives from Stripe only the information needed to deliver and support your license: your name, email address, and order details. We do NOT receive or store your full payment card number. Stripe's own privacy policy applies to data they collect: https://stripe.com/privacy
- PayPal — processed by PayPal. PayPal collects and processes your name, email address, and payment details according to your PayPal account settings. Tetra720 receives from PayPal only the information needed to deliver and support your license: your name, email address, and order details. PayPal's own privacy policy applies: https://www.paypal.com/us/legalhub/privacy-full
- Wire transfer, ACH, or Zelle — sent directly to our business bank account. Your bank processes your identifying information according to their own policies. Tetra720 receives your name, email address (from your accompanying message), and the transferred amount.
- Purchase order — accepted from eligible Tier 1 buyers (publicly traded companies, US federal or state government agencies, accredited universities, major aerospace or defense contractors). We receive whatever information you include on the purchase order and any accompanying correspondence.
When you use C3
C3 stores your license key locally on your computer. To validate that key, C3 may periodically contact our license server using only:
- Your license key
- A hashed (non-reversible) identifier derived from your computer's hardware, used only to prevent the same license from being used on an unlimited number of machines
We do NOT collect your drawings, files, or any content you create with C3. Your work stays on your computer.
If you opt in to crash reporting (off by default), C3 may send us: app version, macOS version, model of Mac, and the technical stack trace of any crash. No drawing content is included.
If you opt in to anonymous usage telemetry (off by default), C3 may send us minimal feature-usage signals (e.g., "user opened the dimension menu") to help us prioritize improvements. No drawing content, no personal identifiers.
You can disable both crash reporting and telemetry at any time in C3's Settings.
When you email us
If you contact us at legal@tetra720.com, support@tetra720.com, or any other Tetra720 address, we receive whatever you include in that email: your name, email address, and the contents of your message. We use this only to respond and to track support history.
3. How we use your information
We use your information only for the purposes listed below:
- To deliver your license key and confirm your purchase
- To validate that your license is being used in accordance with your license agreement
- To respond to your support requests
- To send you essential transactional emails (license delivery, receipts, security notices, EULA updates, end-of-support notices)
- To comply with our legal and tax obligations
- With your opt-in consent, to improve C3 through crash reports and anonymous usage signals
- To measure whether our advertising works, using the website tools described in Sections 2 and 10
We do NOT sell your personal information. We do NOT use your information to train artificial-intelligence models.
Apart from the website advertising measurement described in Sections 2 and 10, we do not share your personal information with advertisers or marketing networks. In particular, we never share your purchase records, license key, support correspondence, or anything you create in C3 with any advertising company. C3 itself contains no advertising trackers of any kind.
4. Legal basis for processing (for users in the European Economic Area and the United Kingdom)
We process your personal information on the following legal bases under GDPR and UK GDPR:
- Contract — processing necessary to deliver and validate the C3 license you purchased
- Legal obligation — processing necessary to meet our tax and accounting duties
- Legitimate interests — operating our website securely, preventing fraud, and improving C3 (where this does not override your rights)
- Consent — for crash reporting and anonymous usage telemetry (which you can withdraw at any time in C3 Settings)
We do not load the Meta advertising pixel for visitors in the European Economic Area, the United Kingdom, or Switzerland. Our advertising measurement described in Sections 2 and 10 does not apply to you.
5. Who we share your information with
We share information only with the following categories of third parties, and only as needed to operate our business:
- Stripe — our credit-card payment processor, for orders paid by card
- PayPal — for orders paid via PayPal
- Our business bank (First Eagle Bank) — for orders paid by wire, ACH, or Zelle
- Resend (or successor transactional-email provider) — to send you license-delivery emails, receipts, and security notices
- Our hosting providers — currently Vercel (for the website and license server, and for the aggregated website analytics described in Sections 2 and 10) and Cloudflare (for DNS)
- Meta Platforms — advertising measurement for visitors to our website only, as described in Sections 2 and 10. Meta never receives your purchase records, license information, or anything you create in C3.
- Government tax authorities — where required by law (the IRS, the Illinois Department of Revenue, and other state or foreign tax authorities where applicable)
- Legal authorities — if we are required by valid legal process (subpoena, court order) to disclose specific information
We do NOT share your information with any other third party for any other purpose without your explicit consent.
6. International transfers
TETRA720 LLC is based in the United States. If you are located outside the U.S., your information will be transferred to and processed in the U.S. and other countries where our service providers operate. Where required by GDPR or UK GDPR, our processors use Standard Contractual Clauses or other lawful transfer mechanisms.
7. How long we keep your information
We keep your information for as long as is necessary for the purposes described above:
- License records (your name, email, license key, purchase date) — for as long as your license is active, plus a period required by tax and accounting law (currently up to 7 years after the last activity on the license)
- Support correspondence — for up to 3 years after the last message in that thread
- Crash reports and telemetry (opt-in) — for up to 24 months
- Website server logs — for up to 90 days
- Website analytics — aggregate counts only, kept indefinitely; these contain no personal information
- Meta pixel data — held by Meta under Meta's own retention policies, which we do not control
After these periods, your information is deleted or irreversibly anonymized.
8. Your rights
Depending on where you live, you have some or all of the following rights regarding your personal information:
- Access — request a copy of the personal information we hold about you
- Correction — ask us to correct inaccurate or incomplete information
- Deletion — ask us to delete information we no longer need a legal reason to keep
- Restriction — ask us to limit how we use your information
- Portability — receive your information in a portable, machine-readable format
- Objection — object to processing based on our legitimate interests
- Withdraw consent — withdraw consent for crash reporting or telemetry at any time in C3 Settings
- Complain to a regulator — if you believe we have not handled your information lawfully, you may complain to your local data protection authority
Residents of California, Colorado, Virginia, Connecticut, Utah, and other U.S. states with comprehensive privacy laws have additional rights under those laws, including the right to know what we collect, the right to delete, and the right to opt out of the sale of personal information or its use for cross-context behavioral advertising.
We do not sell personal information. We do share limited website-visit information with Meta for advertising measurement, as described in Sections 2 and 10. Some state privacy laws classify that as "sharing" for cross-context behavioral advertising. You can opt out at any time using the Your Privacy Choices link in our website footer, or by any of the other methods in Section 10. Opting out does not affect your ability to buy, download, or use C3.
To exercise any of these rights, email legal@tetra720.com with the subject "Privacy Request". We will respond within 30 days (or as required by applicable law). We may need to verify your identity before processing a request.
9. Children
C3 and our website are not directed at children under 16. We do not knowingly collect personal information from children under 16. If you believe a child has provided us with personal information, please contact us at legal@tetra720.com and we will delete it.
10. Cookies, tracking, and your advertising choices
Our website uses:
- Essential cookies necessary for the site to function (for example, to remember your shopping cart).
- Vercel Analytics — cookieless and aggregated. It sets nothing on your device and does not follow you to other sites.
- The Meta pixel — this one is an advertising tracker, and we want to be straightforward about it. It sets cookies belonging to Meta and reports your visit to Meta so we can tell which of our ads are working and show ads to people who have visited our site. We do not load it for visitors in the European Economic Area, the United Kingdom, or Switzerland.
Your advertising choices
This preference is stored in this browser only — if you use another browser or device, set it there too. Turning the pixel off takes effect immediately for every page you load from here on.
You can opt out of the Meta pixel in any of these ways, and none of them affect your ability to buy, download, or use C3:
- Click Your Privacy Choices in the footer of any page on our website. This stores a preference in your browser and stops the pixel from loading.
- Use your browser's tracking protection, private browsing, or any ad blocker. Most of them already block it.
- Change your ad settings on Meta's own platforms at https://www.facebook.com/adpreferences
C3 itself contains no advertising trackers of any kind. Nothing you draw, open, or save in C3 is ever sent to Meta or to any advertising company. This section is about our website only.
11. Security
We use commercially reasonable technical and organizational measures to protect your information, including TLS/HTTPS encryption in transit, encryption at rest for our databases, two-factor authentication on all administrative accounts, principle-of-least-privilege access control, and regular software updates. No method of transmission or storage is 100% secure, but we take this seriously.
If we ever become aware of a security incident affecting your personal information, we will notify you and, where required, the relevant regulator without undue delay and in accordance with applicable law.
12. Changes to this policy
We may update this Policy from time to time. When we make material changes, we will update the "Last updated" date at the top and, for substantive changes affecting your rights, we will notify active license holders by email at the address on file.
13. Contact us
For privacy questions, requests, or complaints: legal@tetra720.com
For postal contact: TETRA720 LLC — [REGISTERED BUSINESS ADDRESS]
© 2026 TETRA720 LLC. All rights reserved.