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Whether you’re a one-person operation or a growing business with a full team, we’re here to help. Get in touch and let’s talk about what we can do for you.
Whether you’re a one-person operation or a growing business with a full team, we’re here to help. Get in touch and let’s talk about what we can do for you.
Neither Microsoft Copilot nor Claude gives anyone access they do not already have. The risk is that your existing permissions are wider than you think, and AI makes that visible in seconds. This guide covers how each tool behaves, what has gone wrong in the real world, and what to fix before you switch either on.
Yes, with one condition. Both work strictly inside the permissions your business has already set, so the risk is not that AI breaks your rules.
Microsoft Copilot
Claude
What it can reach
Only content the signed-in user can already open
Only what you connect and authorise, through OAuth
How it connects
Microsoft Graph, inside the Microsoft 365 service boundary
MCP connectors to Google Drive, Microsoft 365, Slack, GitHub and others
Labels and encryption
Respects Purview sensitivity labels and Azure Rights Management
Follows the permissions the connector and user allow
File handling
Content stays inside your tenant
Retrieved on demand, not cached, credentials encrypted
Model training
Your data is not used to train foundation models
Not used for training without your organisation’s express permission
Six places to go next, depending on what you are trying to work out.
The permissions and oversharing problems that surface first when you switch Copilot on.
How Claude connects to your data, what it can reach, and what to set before you allow it.
The two compared on security, cost and fit for a UK small business.
The five things every policy must cover, plus a free template you can edit this week.
What Microsoft 365 DLP does, what Business Premium includes, and the five policies to start with.
Why years of SharePoint and Teams files become a liability the moment Copilot can search them.
Understanding the specific risks for each platform is essential before deploying Copilot or Claude. Some risks are shared; others are unique to how each tool connects to your data.
15% +
of security leaders name data exposure as their top AI concern
Cloud Security Alliance, 2026
Bank of England, 2024
The primary concern for most organisations. Permission sprawl hidden external links, broken inheritance, mis-aligned groups means users can access far more than intended. When Copilot surfaces that content, the exposure multiplies.
Without consistent sensitivity labels, Microsoft Purview cannot enforce DLP rules. Content that should be restricted financial documents, customer data, HR records can be processed and included in Copilot’s responses if it lacks appropriate classification. Inappropriate classification is just as dangerous as no classification at all.
Attackers may embed malicious instructions hidden in content that Copilot retrieves emails, documents, web content. The “SearchLeak” exploit demonstrated how a crafted q-parameter in a URL could cause Copilot to search a user’s mail and exfiltrate data by embedding content in image URLs. Prompt injection attacks remain one of the most active threat vectors against large language models.
AI agents can be manipulated through phishing or malicious content to reveal or forward sensitive information. As Copilot generates summaries and drafts from across Microsoft services, a single compromised input can influence what other users see.
AI models can produce incorrect or misleading content. If a summary misrepresents financial data or fabricates a quote, the reputational and legal consequences for a business can be serious.
Claude’s strength is its flexible connector model, but that flexibility is a risk if not governed. A connector for Google Drive, Slack, or Microsoft 365 might be granted overly broad scope – write permissions, wide-folder access, or sharing outside organisation boundaries. Without strict access controls, connectors can expose data well beyond what was intended.
Claude’s strength is its flexible connector model, but that flexibility is a risk if not governed. A connector for Google Drive, Slack, or Microsoft 365 might be granted overly broad scope write permissions, wide-folder access, or sharing outside organisation boundaries. Without strict access controls, connectors can expose data well beyond what was intended.
If your organisation does not set custom retention policies, data transcripts, projects, uploaded files may be stored longer than needed. While Claude does not use this data for model training without permission, the data still exists and is still a target.
Similar to Copilot risks. Content arriving via a Slack channel, GitHub repository, or shared drive that contains malicious prompts can manipulate Claude’s behaviour and produce unintended outputs or leak sensitive information.
Once connectors are enabled, files may be shared through Claude in ways users are not fully aware of. Write permissions, if not explicitly restricted, could allow Claude to create or edit content in connected systems.
These are not hypothetical risks.
In early 2026 Microsoft confirmed a bug that let Copilot Chat summarise confidentially labelled emails in Sent and Draft folders, bypassing DLP and sensitivity labels. Fixed in February 2026. Reference CW1226324.
Found by Varonis and reported in January 2026. A crafted link tricked Copilot into exporting user data, including files accessed, meeting details and conversation history, to an external server. Microsoft patched it by mid-January 2026.
In March 2025, over data security concerns. A clear signal of how seriously institutional bodies treat AI tools interacting with sensitive data.
Treat an AI rollout as a security event, not a productivity upgrade. 58% of financial services firms added security controls specifically for their Copilot deployment.
If your business is not yet ready for Copilot or Claude, it is better to pause and prepare properly than to rush ahead and create vulnerabilities. Here are the security measures we recommend and deliver through our AI Data Security Pack.
After completing an AI data security assessment, you receive a detailed report covering your current vulnerabilities, risk levels across both Microsoft Copilot and Claude, and a clear picture of where your data governance stands today.
From there, we provide a prioritised action plan with a realistic timeline for implementing the security measures your business needs. This typically includes permissions cleanup, sensitivity label deployment, DLP policy configuration, and connector governance phased so your team is not overwhelmed.
You also receive a phased roadmap for safe Copilot and Claude deployment, designed around your business’s actual readiness rather than a generic checklist. For some businesses, this means a pilot with a small team before a wider rollout. For others, it means pausing AI adoption entirely until foundational security work is complete.
Ongoing support options include managed security services, regular review schedules to maintain security as AI tools evolve and gain new capabilities, and a staff training programme covering both platforms. We also monitor for emerging threats prompt injection techniques, connector vulnerabilities, platform updates and adjust your defences accordingly.
AI systems can be vulnerable to data poisoning attacks, and malicious prompts can lead to data leakage. The threat landscape around AI is evolving rapidly. Having a partner who stays current with these developments is not a luxury for enterprise users alone it is a practical necessity for any business using AI tools with access to sensitive data.
Your staff are already using AI tools. The only question is whether they are doing it safely. Putting a simple AI usage policy and basic AI governance in place is now essential, not optional. The goal is safe, productive use of AI, not banning it altogether.
The quickest way to find out where you stand is half an hour on a call with Adam. He will talk you through how we approach AI data security, what we would put in place and why, and what we would be watching for in a business like yours. No charge and no expectation that you buy anything.
Yes, provided your organisation has proper governance in place. Microsoft 365 Copilot only surfaces data a user already has permission to access. It respects sensitivity labels and DLP policies configured through Microsoft Purview. However, the CW1226324 bug in early 2026 where Copilot summarised confidentially labelled emails despite protections shows that even well-configured environments can be affected by software vulnerabilities. Regular auditing and monitoring are essential. Copilot can access all sensitive data users can access, which is why permission cleanup matters so much.
Yes, with the right safeguards. Claude uses user-delegated connectors and does not cache file content when connecting to Microsoft 365. It does not use organisational data for model training without explicit permission. However, safe usage depends on restricting connector scopes, applying retention policies, controlling write permissions, and maintaining audit practices. Is Claude AI safe? It is, but only as safe as the governance around it.
Microsoft processes and stores your data prompts, files, responses within its cloud services. For purposes such as bug monitoring and compliance, internal access exists. Microsoft states that organisational data is not used to train foundational AI models unless explicitly allowed. Data sharing with third parties is governed by Microsoft’s Data Protection Addendum and existing privacy policies. Data privacy and security in AI is a legitimate concern, and organisations should review these agreements carefully.
With the same caveats. If the source data (SharePoint, OneDrive, Google Drive) uses appropriate permissions and controls, and connectors are carefully configured with read-only access and restricted write permissions, then yes. Credential storage, SSL, and scope of access must all be audited. Is Claude safe for sensitive data? Only if the environment around it is properly secured.
They are entirely different products. Microsoft 365 Copilot is a productivity tool embedded in apps like Word, Excel, Outlook, and Teams it helps with drafting, summarising, and analysing data across your Microsoft 365 environment. Microsoft Security Copilot is a separate product designed for cybersecurity analysts and SOC teams, focused on threat investigation and incident response. This page covers Microsoft 365 Copilot only.
Microsoft Purview Information Protection enables data classification, sensitivity labelling, encryption, and rights management. It integrates directly with Copilot to enforce access controls sensitivity labels prevent Copilot from processing, summarising, or generating content from protected sources unless the right users have the appropriate rights. Purview also supports DLP policies, auditing, retention policies, and eDiscovery, making it foundational for any AI data security strategy. Microsoft Purview data governance capabilities extend across the full data estate.
Classified data allows policy rules to distinguish between public, internal, and confidential information. This enables DLP to block or warn when sensitive data is used in prompts, prevents sensitive files and emails from being processed by AI, and ensures appropriate encryption. Without data classification, control simply cannot be applied AI tools will treat all accessible content equally, regardless of how sensitive it actually is.
Microsoft 365 Copilot operates entirely within the Microsoft 365 service boundary. It uses Microsoft Graph to surface emails, files, chats and calendar entries, but only content the individual user already has permission to access. Copilot does not create new data access rights. If a member of staff cannot open a document in SharePoint today, Copilot cannot summarise it for them tomorrow.
Copilot also respects sensitivity labels and encryption applied through Microsoft Purview Information Protection. Content labelled Highly Confidential with Azure Rights Management encryption requires explicit EXTRACT or VIEW rights before Copilot can process it.
Microsoft states that organisational data processed by Microsoft 365 Copilot is not used to train foundational AI models. Users and administrators can also opt out of personalisation features.
Claude uses a connector model called MCP, the Model Context Protocol, to integrate with external data sources: Google Drive, Microsoft 365, Slack, GitHub and others. Access is user-delegated through OAuth, so Claude only sees what the connector and the authenticated user’s permissions allow. There is no elevated service account quietly reading everything in the background.
The Microsoft 365 connector retrieves data on demand. It does not cache file content, credentials are encrypted, and data remains in your tenant. Claude does not use your prompts, outputs or files for model training without your organisation’s express permission, and retention follows whatever policy your organisation sets.