Is it safe to connect Sage to ChatGPT or Claude?

Connecting Sage to ChatGPT or Claude is safe when you control three things: what the connector can reach, what the AI assistant keeps from the conversation, and the GDPR basics around both. Get those right and an AI assistant is no riskier than the reporting tools and spreadsheets your team uses today. Get them wrong, for example company figures in a personal ChatGPT account with training switched on, and it's a real problem.

This guide covers each part, with a checklist at the end for your IT lead or data protection officer. Vendor terms change; the details below were checked in October 2026.

What the AI can and can't touch

An AI assistant reaches Sage through an MCP server, a connector that gives it a set of tools for reading your data. What the assistant can do depends entirely on that connector. With Insights AI, Zynk's Sage MCP server:

• It's read-only. The assistant can read customers, suppliers, invoices, transactions and balances. It can't post, edit or delete anything in Sage.
• It respects your Sage permissions. It connects with a Sage login and only sees what that login can see. Give it a login with the access the AI needs, and no more.
• There's no copy of your ledger. Answers are read live from Sage when someone asks, rather than copied into a separate data warehouse.
• Every answer is traceable. The assistant can show the records behind a figure, so answers can be checked.
• You can switch it off. Disconnect it from the assistant, or remove its access, at any time.

What the connector can't control is the conversation itself. When the assistant answers "which customers owe us more than £10,000?", those names and figures become part of a chat stored by OpenAI, Anthropic, Microsoft or Google. That is the second thing to get right.

What ChatGPT and Claude do with your conversations

The plan you're on makes the biggest difference:

Plan	Used to train the vendor's models?	Data processing agreement
ChatGPT Free, Go, Plus, Pro (personal)	Yes, unless you turn off "Improve the model for everyone" in Settings > Data controls	No
ChatGPT Business, Enterprise, Edu	No, by default	Yes
Claude Free, Pro, Max (personal)	Your choice, in Settings > Privacy ("Help improve our AI models")	No
Claude Team, Enterprise	Never	Yes, part of the commercial terms

A few details matter for finance data:

• Retention. On Claude's personal plans, conversations you allow for training can be kept for up to five years, against 30 days if training is off. ChatGPT business admins set their own retention, and deleted chats on both services are removed within 30 days.
• Where data lives. ChatGPT Enterprise and Edu can store data in the UK or the EU through OpenAI's data residency option. Claude currently stores data in the US, with no UK or EU option. Anthropic's DPA includes EU standard contractual clauses and the UK Addendum for international transfers.
• Admin control. On ChatGPT Business and Claude Team, only admins or owners can add custom connectors, so staff can't connect company systems on their own.

The practical rule: use a business plan for company financial data, and if anyone uses a personal plan for work, make sure training is switched off and it's covered by your AI policy.

GDPR: what to cover

Sage holds personal data: customer and supplier contact names, sole traders' details, and sometimes staff information. So connecting it to an AI assistant is processing under UK GDPR. You stay the controller; the AI vendor, on a business plan, acts as your processor. Points to cover:

• A data processing agreement with the AI vendor. Business plans include one; personal plans don't.
• Lawful basis. Internal reporting is often covered by legitimate interests; record your reasoning.
• International transfers. Note where the vendor stores and processes data, and the safeguards in its DPA.
• A DPIA. The ICO expects a data protection impact assessment for many uses of new technology like AI. Even a short one shows you've thought it through.
• Data minimisation. Connect with a Sage login limited to what the AI needs.
• Transparency. Check whether your privacy notice should mention AI processors.
• Staff guidance. Which assistant and plan to use, and what not to paste in.

This isn't legal advice. Your DPO or adviser should confirm what applies to you.

Zynk's security and compliance

Zynk is ISO 27001 certified, complies with UK GDPR and EU GDPR, and is registered with the Information Commissioner's Office. Our security and compliance documentation is in our Trust Centre, and more detail is on our security page.

A sign-off checklist for IT and your DPO

• The assistant is on a business plan (ChatGPT Business or Enterprise, Claude Team or Enterprise, or your Microsoft or Google enterprise agreement), with a DPA in place
• Training on your conversations is confirmed off
• The connector is read-only and uses a Sage login with only the access it needs
• Only admins can add connectors to the assistant
• Data location and transfer safeguards are recorded
• Your lawful basis, and a DPIA if needed, are recorded, and your privacy notice is checked
• Staff have guidance on which assistant to use and what not to paste in
• A review date is set, because vendor terms change

Next steps

When you're ready to connect, our guide shows how to connect Sage to ChatGPT, Claude, Copilot or Gemini. You can also read about the Sage MCP server or talk to our team about your security questionnaire.