If you're running a website today, you're almost certainly using third-party services. Analytics, advertising, payment processing, email marketing, customer chat, social sharing—these services provide functionality that would be impractical to build yourself. But every third-party service you add introduces data flows that need to be disclosed in your privacy policy.
This is one of the most commonly overlooked aspects of privacy compliance. Businesses spend time crafting privacy policies about their own data practices, then forget to mention that Google, Facebook, Stripe, and a dozen other companies are also collecting data through their website.
Why Third-Party Disclosure Matters
When you add a third-party service to your website, you're typically allowing that service to collect data directly from your visitors. An analytics pixel loads, a cookie gets set, data flows to the third party's servers. Your visitors might never realize this is happening unless you tell them.
Privacy laws generally require transparency about these data flows:
GDPR requires disclosure of any recipients or categories of recipients of personal data, including third parties.
CCPA requires disclosure of categories of third parties with whom personal information is shared, and specific requirements for "sales" of data.
Service requirements often mandate disclosure too. Google Analytics, Google AdSense, and many other services explicitly require you to disclose their use in your privacy policy.
Common Third-Party Categories
Analytics Services
Google Analytics is ubiquitous, but there are many others—Adobe Analytics, Mixpanel, Amplitude, Matomo, Plausible, and more. These services track how visitors interact with your website—pages visited, time on site, clicks, scrolls, and often demographic and interest data.
Analytics services typically use cookies and may collect IP addresses, device information, and browsing behavior. This data is personal information under most privacy laws, even if it doesn't include names or emails.
Disclosure should cover: What analytics service you use, what data it collects, the purposes (understanding user behavior, improving the website), and where users can find more information (link to the service's privacy policy).
Advertising and Marketing
If you run ads, you're likely using services like Google Ads, Facebook Ads, or programmatic advertising networks. These services place tracking pixels on your site to measure conversions, build audiences, and enable retargeting.
Advertising tracking is often the most privacy-invasive category of third-party services. It can involve cross-site tracking, building detailed profiles of user interests, and sharing data with numerous ad tech vendors.
Disclosure should cover: That you use advertising services, what data they collect, the purpose (serving relevant ads, measuring campaign effectiveness), opt-out mechanisms (both your own and the services' opt-out tools), and relevant information for CCPA "sale" opt-outs if applicable.
Payment Processing
When visitors make purchases, their payment information flows through payment processors like Stripe, PayPal, Square, or Braintree. These services handle highly sensitive financial data.
The good news is that reputable payment processors have robust security and privacy programs. The key disclosure point is clarifying that you don't store full payment card details yourself—the processor handles that.
Disclosure should cover: Who processes payments, confirmation that you don't store complete card numbers, what transaction data you do retain (order history, shipping addresses), and links to the processor's privacy policy.
Email Marketing
Services like Mailchimp, Klaviyo, ConvertKit, or ActiveCampaign store your email list and send your campaigns. They also track email engagement—opens, clicks, and sometimes subsequent website visits.
Disclosure should cover: That you use an email marketing service, what subscriber data is shared with them, how that data is used (sending emails, tracking engagement), and unsubscribe procedures.
Customer Support and Chat
Live chat tools (Intercom, Zendesk, Drift) and customer support platforms collect visitor information, conversation history, and often track on-site behavior to provide context to support agents.
Disclosure should cover: That chat or support tools collect data, what data is collected, how it's used (providing support, improving service), and retention practices for conversation history.
Social Media Integration
Social sharing buttons, embedded feeds, and login-with-Facebook/Google features all involve third-party data collection. Even if visitors don't click the share button, the embedded code often tracks their presence on your site.
Disclosure should cover: That social media plugins are present, that these services may collect data even without interaction, and links to the relevant social platforms' privacy policies.
CDN and Hosting Services
Content delivery networks (Cloudflare, Fastly) and hosting platforms (AWS, Google Cloud, Vercel) process traffic to your website. They typically log IP addresses and may provide security services that analyze traffic patterns.
These are usually considered necessary for website operation, but transparency is still good practice.
Embedded Content
YouTube videos, Google Maps, Instagram embeds—third-party content embedded on your pages loads from the third party's servers, allowing them to set cookies and track visitors.
Disclosure should cover: Types of embedded content, that accessing this content involves data transfer to the content provider, and links to relevant privacy policies.
How to Structure Third-Party Disclosures
There's no single required format, but effective disclosure typically includes:
List by Category
Group services by type rather than listing every vendor alphabetically. Users understand "advertising partners" better than a list of unfamiliar ad tech company names.
Explain the Purpose
Don't just say you use Google Analytics. Explain why—to understand how visitors use the website and improve user experience. Context helps users make informed decisions.
Describe Data Involved
Be specific about what data each category of service collects. "Browsing behavior, device information, and IP address" is more meaningful than "usage data."
Link to Service Privacy Policies
For major services, link to their privacy policies. This gives users access to detailed information without cluttering your policy.
Provide Opt-Out Information
Where applicable, explain how users can opt out of tracking or limit data collection. For advertising, this might include links to the Digital Advertising Alliance opt-out page, Google's ad settings, or your own cookie preferences mechanism.
Auditing Your Third Parties
You can't disclose what you don't know about. Regularly audit what third-party services are actually running on your website.
Technical Review
Use browser developer tools to see what external requests your pages make. Tools like Ghostery or Privacy Badger can help identify trackers. For a thorough audit, consider services that scan your site and catalog all third-party connections.
Contract Review
Check your vendor agreements. What data processing are you authorizing? What are their obligations for data protection? Do you have appropriate Data Processing Agreements (DPAs) where required by GDPR?
Tag Management
If you use a tag manager (Google Tag Manager, Segment), audit what's actually being deployed. Tag managers make it easy to add tracking—so easy that you might have scripts you've forgotten about.
Keeping Disclosures Current
Your third-party services change over time. You add new tools, remove old ones, vendors update their practices. Your privacy policy needs to keep pace.
Update when adding services: Before deploying a new analytics tool or advertising pixel, check whether your privacy policy needs updating.
Periodic reviews: Schedule regular privacy policy reviews—quarterly is reasonable for most businesses.
Monitor vendor changes: Major vendors occasionally notify customers of significant privacy practice changes. Pay attention to these notices and update your disclosures accordingly.
The Balance Between Thoroughness and Readability
There's a tension in third-party disclosure between being comprehensive and keeping your privacy policy readable. Listing every tracking pixel from every ad network creates accuracy but destroys usability.
The practical approach is category-based disclosure with appropriate detail. Explain the types of services you use, the general data practices involved, and provide mechanisms (links, opt-outs) for users who want to dig deeper.
Your goal is informed consent and transparency, not overwhelming users with a phone-book-length list of vendor names. Regulators and users alike appreciate clarity over exhaustive but incomprehensible detail.