Copilot vs ChatGPT: Which AI Tool Better Protects a Lawyer’s Privacy?

Both Microsoft Copilot and ChatGPT can help lawyers work faster. But when every prompt may include confidential client data, speed isn’t the only thing that matters.

AI tools are now daily essentials. In law firms, Copilot and ChatGPT help lawyers draft contracts, refine clauses, and analyze agreements, increasing efficiency as well as the potential for confidential data exposure.

This guide compares the privacy practices, data handling, and security of these AI tools and assesses which is safer for sensitive legal work. For lawyers, privacy means protecting attorney-client privilege and client trust. Let’s see which tool does it best.

Key Takeaways

• Microsoft 365 Copilot stores data within a firm’s tenant, encrypts it, and excludes training by default. OpenAI’s ChatGPT’s consumer tiers (Free and Plus) may store and train on user inputs.
  
• Only Copilot Enterprise and ChatGPT Enterprise/API tiers offer compliance-grade privacy controls, administrative oversight, and data isolation suitable for legal work.
  
• Lawyers should use enterprise AI tools or Spellbook, the legal-specific AI built for Word with zero data retention and full encryption to safeguard attorney-client privilege.

Head-to-Head Comparison: Copilot vs ChatGPT Privacy for Lawyers

As AI tools transform law practice, how do Copilot and ChatGPT protect sensitive data? Below is a lawyer-focused comparison.

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For another side-by-side look at consumer AI privacy, see Perplexity vs ChatGPT privacy.

Data Handling

Copilot runs in a Microsoft 365 tenant via Microsoft Graph, keeping content within a firm’s cloud boundary and excluding data from model training in enterprise setups. 

ChatGPT processes prompts on OpenAI servers. In Free/Plus plans, user prompts and content may be stored and used to improve models, unless you opt out in settings. In Business and Enterprise tiers, training is disabled by default. All options offer administrative controls over data retention and access, and store user data temporarily or permanently, depending on usage, with differences in retention policies.

Both providers share data only for legal compliance or explicit user consent.

To choose, evaluate how each platform collects and stores user interactions and whether it processes personal and non-personal data for system improvement and learning.

For a deeper look at how ChatGPT collects, stores, and uses data, see our detailed guide on its privacy practices.

Risks of Data Exposure

ChatGPT Free may store chats for training, which increases exposure risk. Plus behaves similarly unless chat history is turned off.  Meanwhile, Copilot retains data within your cloud’s boundary. Your data is not used to train the LLM model. CoPilot’s activity is subject to Microsoft Purview controls (data loss prevention, retention, eDiscovery), which offer administrative oversight and position it as the safer default for law firms. 

For enterprise users in both systems, the AI assistant only accesses data that the human user asking the question already has permission to view, improving control over confidential information.

Lawyers should avoid entering privileged client facts into either tool unless contractual privacy safeguards and retention controls are in place. For sensitive matters, stick to enterprise configurations, anonymize client information, and limit the scope of the sensitive data entered.

Model Training Practices

ChatGPT’s Free/Plus tiers may use user-submitted data for training, while Business and Enterprise plans disable training by default. Microsoft Copilot similarly excludes user data and content from model training in enterprise environments. 

To avoid waiving attorney-client privilege, the best practice is to use configurations where data is not used for training or where any learning is fully anonymized. For legal work, enterprise-configured Copilot is generally the safer choice due to tenant isolation, administrative controls, and contractual limits on training use. 

Security Model

Copilot benefits from Microsoft’s enterprise-grade infrastructure, including encryption, secure servers, and compliance with ISO 27001, SOC 2, and GDPR standards. ChatGPT uses TLS and AES-256 encryption to protect stored and transmitted data, but offers fewer administrative controls. 

Microsoft and OpenAI regularly review their data privacy policies, update their privacy measures in response to evolving security threats and regulatory requirements, and comply with strict privacy and security guidelines. 

Get the full picture on Copilot’s security, retention, and compliance in our Copilot privacy guide.

Integration with Legal Workflows

Copilot integrates directly into Microsoft Word, Excel, Outlook, and Teams, where most legal drafting and contract review already occur. ChatGPT operates through OpenAI’s web interface or connected third-party apps. Firms apply user permissions and transparency on data usage in both platforms to manage exposure.

Copilot’s Microsoft 365 integration adds governance layers, such as Purview audit logs and retention controls, that are not native to ChatGPT. Because it is embedded in the tools lawyers use daily (Word, Outlook) and governed by the firm's existing compliance tools, Copilot remains the more seamless, legal workflow-aligned option.

Attorney-Client Privilege Risk

Inputting sensitive information into any AI tool can compromise confidentiality. Copilot’s enterprise setup adds strong data segregation, encryption, and administrative controls. For maximum security and legal protection, lawyers should use Microsoft 365 Copilot in an enterprise configuration.

Version Comparison: Consumer vs Business Tools

Not all AI versions are created equal, especially when privacy and compliance are at stake. Choosing the right one can determine whether your client data stays protected or exposed.

Microsoft Copilot for Individuals vs. Microsoft 365 Copilot

Copilot for Individuals (Free/Pro) runs under consumer terms with limited privacy controls and no tenant isolation, making it unsuitable for confidential or privileged legal work. Microsoft 365 Copilot runs inside your firm’s tenant under the Data Protection Addendum and Product Terms, with encryption, role-based access, audit logs, and no model training on tenant content. 

ChatGPT Free vs. Plus vs. Enterprise

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For sensitive or privileged legal matters, law firms should use Enterprise versions or the API with zero data retention. Crucially, avoid using Free or Plus tiers for any client data.

How to Protect Your Privacy Using Copilot and ChatGPT

Your privacy settings determine your risk. Configure Copilot and ChatGPT to minimize exposure and preserve confidentiality.

• Use Microsoft 365 Copilot or ChatGPT Enterprise for privileged work.
• In ChatGPT, open Settings → Data Controls and opt out of “Improve the model for everyone.” Use Temporary Chat for short-lived sessions.
• Set and review retention, audit, and access controls. Verify privacy statements and policy changes on a schedule.
• Keep documents inside your Microsoft 365 tenant or another secure repository. Use VPNs, encrypted devices, and least-privilege permissions.
• Do not input client names, facts, or clauses into consumer tools. If needed, use anonymized hypotheticals.
• Periodically clear the history and shared links. Revoke shared links, delete original chats, and use data export or account deletion when appropriate.

For highly sensitive legal work, use Spellbook, an AI tool built for lawyers that works directly in Word, eliminating the need to copy and paste confidential text into a separate web interface. 

Work Confidently with Your Legal Data Using Spellbook

Spellbook is the lawyer-first AI assistant built for confidentiality and control. It never trains on your input or contracts, applies end-to-end encryption, and uses zero data retention with compliance-ready safeguards. Protect client privilege while drafting, reviewing, and redlining legal documents. 

Ready to work faster and safer? Explore Spellbook, the AI built for lawyers who prioritize trust and privacy.

Frequently Asked Questions

Does Copilot Retain Data Indefinitely?

No. Microsoft Copilot for enterprise environments offers granular retention controls, and users can configure deletion schedules. Free or consumer versions retain conversations for a set period (e.g., 18 months) and allow the user to manually delete their history.

Do ChatGPT and Copilot Maintain GDPR Compliance?

Yes, both comply with GDPR and similar frameworks, such as CCPA. However, compliance does not equal confidentiality—lawyers should still verify encryption, access, and retention practices.

Do Copilot and ChatGPT Use AI to Store Personal Information?

Yes, both platforms store conversations (prompts and responses), including any personal information you enter. The underlying service layers use this data for functions like chat history retrieval and context for multi-turn conversations. Still, the use of data for model improvement is strictly conditional on the version and user/admin settings.