Privacy Policy

1. Overview

CheckMCC ("we," "our," or "the service") is a website and browser extension that helps users maximize credit card rewards by displaying Merchant Category Codes (MCC) and eligible credit cards for merchants. We are committed to protecting your privacy and being transparent about the data we collect.

2. Information We Collect

2.1. Website Domain Names

When you use our browser extension, it automatically detects the domain name (e.g., "amazon.com", "shopee.sg") to:

• Look up the Merchant Category Code (MCC) for that website
• Display eligible credit cards for that merchant category
• Allow you to submit new stores to our database (optional)

2.2. Browser Extension Storage

The browser extension stores the following data locally on your device using Chrome's storage API:

• Current domain - The website you're currently visiting
• MCC code - The merchant category code for that domain
• Category - Human-readable category name (e.g., "General Retail")
• Eligible cards - List of credit cards eligible for rewards
• Timestamp - When the data was last fetched (for cache expiration)

This data is stored locally on your device and is NOT synced to cloud storage or shared with anyone.

2.3. User-Submitted Data (Optional)

If you choose to submit a new store to our database through the extension or website, we collect:

• Store name - The merchant's name (e.g., "Amazon")
• MCC code - The 4-digit merchant category code you provide
• Country - The store's country (2-letter code, e.g., "SG" for Singapore)
• Website URL - The store's website address

This data is submitted to our server to improve our database for all users.

3. Information We DON'T Collect

We do NOT collect:

• Browsing history - We only know the current domain you're viewing, not your full browsing history
• Page content - We don't read or analyze the content of web pages you visit
• Personal information - We don't collect your name, email, phone number, or address
• Credentials - We don't access your passwords, credit card numbers, or login information
• Cookies - We don't read or set cookies on websites you visit
• Location data - We don't track your physical location
• Device fingerprinting - We don't create unique identifiers for your device

4. How We Use Your Information

We use the collected data solely to:

• Look up and display MCC codes for merchants you visit
• Show eligible credit cards for those merchants
• Improve our database when you submit new stores
• Cache results locally to reduce API calls and improve performance

5. Data Sharing and Disclosure

We do NOT sell, rent, or share your data with third parties for marketing or advertising purposes.

5.1. API Communication

The browser extension communicates with our backend API at check-mcc.sg to:

• Fetch MCC and card eligibility data by domain
• Submit new stores to our database (user-initiated)
• Fetch valid MCC codes for form validation

These API calls only transmit domain names or store submission data. No personal information is sent.

5.2. Service Providers

We use the following third-party services:

• Vercel - Hosting platform for the website
• MongoDB Atlas - Database for MCC and store data
• Chrome Web Store - Hosts and distributes the browser extension
• PostHog - Analytics (with user consent, can be disabled)

6. Data Storage and Retention

6.1. Local Storage (Browser Extension)

All extension data is stored locally on your device using Chrome's chrome.storage.local API. This data:

• Remains on your device and is NOT synced to the cloud
• Is automatically cleared when you uninstall the extension
• Has a 5-minute cache expiration for domain lookups

6.2. Server Data

When you submit a store to our database, the information is stored on our servers. This data:

• Is used to improve the MCC database for all users
• May be visible to other users who query the same domain
• Is stored securely and accessed only for legitimate purposes

7. Data Security

We implement security measures to protect your data:

• HTTPS encryption - All API communications use HTTPS/TLS
• Local-only storage - Cached data stays on your device
• No sensitive data - We don't collect personal or financial information
• Minimal data collection - We only collect what's necessary for the service to function

8. Analytics

We use PostHog for analytics to understand how users interact with our service. This helps us improve the user experience. PostHog analytics:

• Tracks page views and user interactions (e.g., clicks, searches)
• Does NOT collect personal information by default
• Can be disabled by users who opt out of analytics
• Is used solely for product improvement, not advertising

You can opt out of analytics at any time through your browser settings or by not using the service.

9. Your Rights and Choices

You have the following rights regarding your data:

• Access - You can view the extension's stored data in Chrome's extension settings
• Deletion - You can clear all extension data by uninstalling the extension
• Opt-out - You can disable the extension at any time through Chrome's extension settings
• No tracking - We don't track you, so there's nothing to opt-out of

10. Children's Privacy

Our service is not intended for children under the age of 13. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe your child has provided us with personal information, please contact us, and we will delete such information.

11. Changes to This Privacy Policy

We may update this privacy policy from time to time. We will notify users of any material changes by:

• Updating the "Last updated" date at the top of this policy
• Posting a notice on our website

Your continued use of the service after any changes indicates your acceptance of the updated policy.

12. Contact Us

If you have questions, concerns, or requests regarding this privacy policy or our data practices, please contact us: