How to Give Claude Access to Your Company Documents (UK Guide)

To let Claude answer from your company documents, you have four realistic routes: attach files to a chat, keep them in a project, connect a knowledge base through an MCP server, or query a knowledge-base API from your own systems. Uploads suit a one-off question; a connected knowledge base suits a team, a growing set of documents and more than one tool. Below, each route is explained step by step, together with the UK GDPR points your data protection lead will want answered.

Start with the question you want answered

Most organisations begin with a vague goal ("let the AI read our SharePoint") and end up disappointed. A better starting point is a short list of real questions: "How many days' notice does a contractor need to give?", "Which supplier handles our fire alarm servicing?", "What does our expenses policy say about rail travel in first class?". Those questions tell you which documents matter, how often they change and who needs the answers, and that in turn points to the right option.

Uploads and projects: quick, but they do not scale

Attaching a PDF or Word document to a message is the fastest way to give Claude access to files. Ask it to answer only from the attachment and to quote the clause it relies on, then check that quote against the original. For a single contract or a board paper, that is often all you need.

Projects, available depending on your offer, go one step further: you store reference files and instructions once and reuse them across conversations. Supported formats, storage limits and sharing with colleagues differ between plans, so check the official documentation rather than relying on a blog post (including this one). The structural limits stay the same, though:

• Every copy has to be refreshed by hand when a policy is revised.
• The files are only available inside that one application, not to Cursor or your intranet bot.
• Large documents are read in full, which uses up the conversation's context and makes precise retrieval harder.
• There is no single place to check which version an answer came from.

Connecting a knowledge base to Claude over MCP

The Model Context Protocol is an open standard that lets an assistant call external tools. Connected to a knowledge base, Claude no longer needs the documents pasted in: it asks the base, which searches your corpus and returns only the relevant passages with their sources. Your documents stay in one maintained place, and the RAG as a service model means nobody in your team has to run a search infrastructure.

Step by step with Kopik

1. Create a private base and upload your PDFs, Word documents, text or Markdown files. Kopik extracts, splits and indexes them for hybrid search (full text plus semantic widening of the keywords). Creating a base is free.
2. Generate an API key in your dashboard. It begins with `kpk_` and travels in the `Authorization: Bearer kpk_…` header.
3. Choose the address. `https://kopik.io/api/mcp` covers the whole catalogue; `https://kopik.io/api/mcp?base=<slug>` covers one base, and each base page displays its own. The single-base address also works for private bases with your key.
4. Register the server. In Claude Code: `claude mcp add --transport http kopik https://kopik.io/api/mcp --header "Authorization: Bearer kpk_…"`. Under zsh, keep quotes around any URL containing `?`.
5. In Cursor (`.cursor/mcp.json`) or any client using an `mcpServers` file: `{ "mcpServers": { "kopik": { "url": "https://kopik.io/api/mcp", "headers": { "Authorization": "Bearer kpk_…" } } } }`.
6. Test it with one of your real questions and read the numbered sources.

The server uses the stateless Streamable HTTP transport and exposes three tools: `list_bases` (free, the only one that works without a key), `ask_base` (a drafted answer with numbered source passages) and `search_base` (passages only, same price). On a single-base address you leave out the `base` argument. Setting `maxPriceCents` makes a call fail without charge if a base costs more than you have allowed. For the Claude desktop and web apps, the way to add a remote server depends on your plan, so follow the official help pages.

Using the API for your own applications

When answers need to appear in a helpdesk, an intranet page or an automated workflow, the REST API is the right layer. The same private base answers with the same `kpk_` key, so your internal bot and Claude read identical documents. Questions to your own bases are free within reasonable use (200 a day). Limits are 20 questions a minute and 1,000 a day per user, plus 120 requests a minute per IP address. Everything is documented on the developer page.

UK GDPR and confidentiality: the trade-offs

Under UK GDPR, sending documents that contain personal data to an AI service is processing, and the usual rules apply. The ICO's guidance on AI and data protection is the reference here. In practice, work through these points:

• Lawful basis and purpose. Is answering staff questions from HR files compatible with why the data was collected?
• Data minimisation. Uploads send entire files; retrieval sends only the passages relevant to each question. Where you can, remove personal data from documents that do not need it.
• Processors and contracts. Each provider in the chain needs appropriate terms. Check whether your plan's terms allow your data to be used for training and how long it is kept.
• International transfers. Find out where each service processes data and which transfer mechanism applies. The GDPR and international data transfers base gathers the EU texts that UK rules grew out of.
• DPIA. A data protection impact assessment is wise for any large-scale use involving employee or customer data.
• Access and keys. A private base is visible only to its owner and their API keys. Store keys in a secrets manager and revoke them when people leave.

When a hosted knowledge base beats uploading files

Keep using uploads for the occasional personal question. Move to a hosted knowledge base when:

• your documents run to hundreds of pages, or grow every month;
• several colleagues ask about the same policies and procedures;
• you use more than one assistant or tool and want a single source of truth;
• answers must point to the exact passage for checking;
• out-of-date copies would cause real errors, for example in health and safety or HR.

A sensible rollout is to pilot with uploads, list the questions that come up again and again, then move the relevant documents into a private base and connect it to the tools your team already uses.