Privacy Policy
Last updated: February 26, 2026
1. Introduction
MarginStack ("we", "us", "our") operates the website at marginstack.io. This Privacy Policy explains what information we collect, how we use it, and your rights regarding your data.
2. Information We Collect
Account Information
When you create an account, we collect your email address and name (or the name associated with your Google account if you sign in with Google). If you subscribe to a paid plan, our payment processor collects your billing information directly; we do not store your credit card details.
Calculation Data
When you use the calculator, we receive the product details you enter, including product descriptions, FOB prices, country of origin, weight, dimensions, and HS codes. We use this data to perform calculations and, for logged-in users, to save your calculation history.
Usage Data
We collect anonymous usage data such as pages visited, features used, and calculation counts. This helps us understand how the Service is used and improve it.
Log Data
Our servers automatically record information about your visit, including your IP address, browser type, referring page, and the date and time of your request. This data is used for security and troubleshooting purposes.
3. How We Use Your Information
We use your information to:
- Provide, maintain, and improve the Service.
- Process your calculations and display results.
- Manage your account and subscription.
- Send transactional emails (account confirmation, password reset, billing receipts).
- Send product updates or tariff alerts, if you have opted in to receive them. You can unsubscribe at any time.
- Analyze usage patterns to improve the Service.
- Detect and prevent fraud or abuse.
4. Third-Party Services
We use the following third-party services to operate MarginStack. Each has its own privacy policy governing how it handles your data:
- Supabase (database and authentication): Stores your account information and calculation data.
- Vercel (hosting): Serves the website and processes requests.
- Paddle (payment processing): Handles subscription billing. We do not store your payment card details.
- PostHog (analytics): Collects anonymous usage data to help us improve the product.
- Anthropic (Claude API): Processes product descriptions for HS code classification. Product descriptions sent for classification are not stored by Anthropic beyond the processing window.
- Resend (email): Delivers transactional and notification emails.
5. Data Retention
We retain your account data and calculation history for as long as your account is active. If you delete your account, we will remove your personal data within 30 days, except where we are required by law to retain it.
6. Data Security
We use industry-standard security measures to protect your data, including encryption in transit (HTTPS) and at rest. However, no method of transmission or storage is 100% secure, and we cannot guarantee absolute security.
7. Cookies
We use essential cookies to manage authentication sessions. Our analytics provider (PostHog) may use cookies or similar technologies to track anonymous usage. We do not use advertising cookies or sell your data to advertisers.
8. Your Rights
Depending on your jurisdiction, you may have the right to:
- Access the personal data we hold about you.
- Request correction of inaccurate data.
- Request deletion of your data.
- Object to or restrict certain processing of your data.
- Request a portable copy of your data.
To exercise any of these rights, contact us at hello@marginstack.io.
9. Children's Privacy
The Service is not directed at children under 16. We do not knowingly collect personal data from children. If you believe a child has provided us with personal data, please contact us and we will delete it.
10. Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of material changes by updating the "Last updated" date at the top of this page.
11. Contact
If you have questions about this Privacy Policy, contact us at hello@marginstack.io.
See also our Terms of Service and Refund Policy.