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Purpose Limitation

Purpose limitation is the rule that personal data collected for one purpose should not be reused for an unrelated one. It is the privacy principle most directly tied to vendors training AI on your data.

What is purpose limitation?

Purpose limitation is the rule that personal data collected for one purpose should not be reused for an unrelated one. Under GDPR Article 5(1)(b), data must be "collected for specified, explicit and legitimate purposes" and not used later in a way that is "incompatible with those purposes."

A new use is not always banned. Article 6(4) lists what to weigh, such as how close the new purpose is to the old one and what people would expect.

California's CCPA has a similar idea. Its statute requires contracts that bar a service provider from using personal information for purposes outside the contract.

A real change we caught

Venpo flagged this change: Lovable now trains its AI on your prompts and code by default. Its privacy policy, effective September 9, 2026, uses prompts, code and project files on Free and Pro plans to train its AI models by default, unless you opt out. Data you sent to build an app now also serves a second purpose: training the vendor's AI.

Why it matters to you

Purpose limitation is where AI training meets privacy law. You shared data so a vendor could run a service. If the vendor also uses it to train models, that is a new purpose. As the controller, you may need to explain it to your users or stop it. Your own customers may also have been promised that their data is used only to deliver your service.

What to check

  • The purposes listed in the vendor's DPA and privacy policy, and whether they stop at providing the service.
  • Broad purposes such as "improving our products" or "developing new services."
  • Whether AI training is on, off or opt-out by default. See AI training opt-out.

Data Minimization

Read the full page on Data Minimization

Data minimization means collecting and keeping only the personal data you need. Article 5(1)(c) requires data to be "adequate, relevant and limited to what is necessary" for its purpose.

Article 25(2) builds this into defaults. By default, only data needed for each purpose should be processed. That covers how much is collected, how long it is kept and who can see it.

The CCPA says something close: under its statute, use for a business purpose must be "reasonably necessary and proportionate."

With vendors, minimization is practical. Sync only the fields a tool needs, turn off features that collect more than you use, and check retention settings. Less data sent means less to lose if a vendor has a breach, and less for a vendor to reuse if its terms change later.

How Venpo helps

Venpo monitors your vendors' privacy policies, terms and DPAs and emails you when they add new purposes for your data. The Fine Print Scan answers whether each vendor trains AI on your data and how long it keeps it.

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Frequently asked questions

Is AI training a new purpose under the GDPR?

It can be. If data was collected to provide a service, training a model on it may be a different purpose that needs its own check and legal basis.

What is an example of purpose limitation?

A support tool collects customer emails to answer tickets. Using those same emails to send marketing would be a new purpose that needs its own justification.

Related terms

AI and Your Data AI Training on Customer Data AI training on customer data is when a vendor uses the information you put into its product, such as files, prompts and AI answers, to teach or improve its AI models. How Vendors Use Your Data Data Retention Data retention is how long a vendor keeps your data, including your content, account details, logs and backups, both while you use the service and after you leave. Data Roles and Data Types Personal Data Personal data is any information about a person who can be identified, directly or by combining details. Under the GDPR it can include names, work emails, IP addresses and cookie IDs. AI and Your Data AI Training Opt-Out An AI training opt-out is a setting, request or contract clause that tells a vendor not to use your data to train its AI models when training would otherwise be on by default. Laws and Regulations GDPR for US SaaS Companies The GDPR is the EU law on personal data. It can apply to a US SaaS company with no EU office if it offers services to people in the EU or tracks their behavior there, and it sets rules for every vendor that handles that data for you. Laws and Regulations CCPA Service Provider Under the CCPA, a service provider is a vendor that processes personal information on your behalf under a written contract that bars it from selling, sharing or reusing that data. With that contract in place, handing data to the vendor is not a sale.

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