Connecting Claude to Pennylane: 8 uses for accounting firms and CFOs (2026)

In spring 2026, connecting Claude to Pennylane required a terminal, an API key and an open-source server maintained by an independent developer. Since early August, Pennylane has offered its own connector, the Pennylane MCP. It is official, it is read-only and it takes a few minutes to set up.

The question is what to ask it. At AI Sisters, an AI consulting firm, we support finance teams and accounting firms in their use of AI. Here is what the connection really makes possible, for accounting firms and for companies, along with its limits. The setup itself is covered in a PDF guide you can download at the end of the article.

In brief

• Pennylane opened its official MCP in early August 2026. It works with Claude, ChatGPT, Mistral and other compatible assistants.
• It is available to accounting firms and companies on a Pennylane Essentiel plan or higher.
• Claude reads, it does not write: no creating, editing or deleting in Pennylane for now.
• It sees what you see, with your access rights. You choose the types of data it can view.
• The value lies in cross-cutting questions: several client files at once, or Pennylane combined with a CRM or a spreadsheet.
• For client data, the choice of Claude account matters: the Team and Enterprise plans do not train models on your conversations.

Also worth reading: Claude in the workplace, the guide for your teams, Claude in Excel and French company data in one question with Claude.

What is the Pennylane MCP?

The Pennylane MCP is a standard plug that lets an AI assistant view your Pennylane workspace.

MCP stands for Model Context Protocol. It is an open protocol, published by Anthropic in late 2024, that most assistants have adopted since. Pennylane hosts the server; you add it to Claude as a connector. The first time you use it, a Pennylane page opens: you log in, choose the firm or the company, then approve the data Claude will be able to access.

Then you ask your questions in plain language. Claude chooses which tools to call: list of client files, invoices, transactions, trial balance, VAT returns. It puts the answer together, and can turn it into an Excel table, a memo or a presentation.

In other words. The MCP works like a visitor badge. Claude enters the Pennylane building with your badge, it can only open the doors you can open yourself, and it cannot move anything. You can take the badge back at any time, from Pennylane or from Claude.

Pennylane already has its own AI, with Copilot, Autopilot, ComptAssistant and configurable agents. It works inside Pennylane. The MCP does something else: it brings the data out to the assistant your teams already use, and combines it with the rest of their tools.

What has changed since the spring

In April 2026, the firm Liberall Conseil published five Claude and Pennylane use cases. With no official connector, it relied on two open-source tools: an MCP server with 87 tools and a Claude Code skill. The article advised against using them in production. Four months later, Pennylane released its own.

The open-source servers still exist, and some go further because they can write to Pennylane. For a firm that is just starting out, the official connector is the sensible starting point: a smaller risk surface, and an accountable vendor behind it.

What Claude can read, and what it does not do

According to Pennylane’s technical documentation, Claude can access almost all of the accounts, but read-only.

What it does not do

No data entry, no reconciliation, no tax filing, no transfers. The history stops at four weeks. Lists come in pages of 100 lines, which slows down very large files. And Claude can make mistakes in a calculation or a grouping: any figure meant for a client must always be checked in Pennylane.

In other words. Claude is a trainee auditor who has been given view-only access. It can leaf through and summarise everything, it prepares your working papers, but it does not hold the pen to post an entry.

For accounting firms: four uses to save time across the portfolio

With a firm connection, Claude sees all the client files you have access to. This is where the MCP adds the most, because Pennylane answers file by file while your questions often cover the whole portfolio.

1. The portfolio review

Today, an engagement manager opens client files one by one to see where things stand. With the MCP, one question is enough: “List my client files on quarterly VAT that have more than 30 transactions awaiting reconciliation.” Pennylane itself gives these two criteria as an example. To start, do it on five files you know by heart and compare with what you know. On 80 files, Claude makes a lot of calls in a row: split by team member or by deadline.

2. The analytical pre-review

Before the review, Claude reads the trial balance, spots accounts that vary sharply from one year to the next and entries above a threshold, then delivers an Excel working paper with the points to justify. It helps you decide where to start; the review and Pennylane’s own checks still have to be done. First task: a file that has already been reviewed, to measure what Claude finds and what it misses.

3. Preparing deadlines

On Monday morning: “Which client files have a VAT return due in the next ten days, and which still have unexplained transactions?” The answer becomes the week’s chase list.

4. The client message

Claude drafts a summary of the file for the business owner: revenue, main expense items, missing documents. The team member proofreads, adjusts the tone and checks every figure before sending.

At BDO, we trained more than 100 accounting professionals in generative AI. The principle is the same: AI prepares, and the profession’s demand for accuracy does not change.

For companies: four uses for the CFO and the business owner

With a company connection, Claude automatically works on your own accounts. The business owner no longer needs to wait for an export to get an answer with figures.

1. The Monday cash review

“List the supplier invoices due in the next 15 days and the expected customer invoices, and build a week-by-week cash plan in Excel.” A CFO often rebuilds this by hand every week. Claude only sees what is in Pennylane, so neither signed commitments without an invoice nor loan repayments that have not been entered.

2. The income statement explained

Claude analyses the income statement, isolates the three items that moved most and traces back to the entries to explain why. Useful before a leadership team meeting, or for a business owner who wants to understand their margin without calling their accountant.

3. Tracking changes

Thanks to the history, you can ask what has been changed on purchase invoices since the last committee meeting. It is a simple check, limited to the last four weeks.

4. Combining with your other tools

Claude can read Pennylane and, in the same conversation, your CRM or an Excel file: it compares deals won with invoices issued, then lists the gaps. Pennylane also mentions combining it with the SIRENE company database through the data.gouv.fr MCP, to check customer records. Missing invoices, however, are still yours to create.

In other words. Pennylane knows your invoices, the CRM knows your sales, the spreadsheet knows your budget. Each has part of the answer. Claude, connected to all three, does the work of the team member who used to open three tabs and copy figures from one to the other.

Client data and professional secrecy: the point to settle first

The MCP protects access to Pennylane. It says nothing about what happens to the data once it reaches Claude. Pennylane points this out: the AI assistant’s terms are the ones that apply.

At Anthropic, the difference depends on the plan. Since autumn 2025, Free, Pro and Max accounts can be used to train models, unless the user opts out in their settings. The Team and Enterprise plans, like the API, fall under the commercial terms: conversations do not train the models. For a firm bound by professional secrecy, or a company handling employee data, this is the first choice to make.

The rest is a matter of discipline: only allow the data types you need, keep the firm connection for people who already have access to the files, and record who approves the deliverables. These rules, along with the connection steps, are set out step by step in our guide.

Moving to setup: our PDF guide

You now know what the connection makes possible. To set it up properly in your firm or finance department, we have put the method together in an eight-page guide:

• the prerequisites: Pennylane and Claude plans, firm or company account;
• connecting step by step, in Claude and in Claude Code;
• setting permissions, data type by data type;
• a test protocol on a file you know, before any client use;
• twelve ready-to-copy prompts, for accounting firms and for companies;
• a usage charter to adapt, and a final checklist.

Would you rather have support? Our AI training for finance starts from your real files, and our AI assessment helps you choose your first use cases based on your maturity. To discuss it, book a 30-minute call.

Key takeaways

• The Pennylane MCP has been official since early August 2026, for Essentiel plans and higher.
• Claude reads everything you can read, but writes nothing: no data entry, no reconciliation, no filing.
• The best uses cut across files or tools: portfolio review, pre-review, cash, combining with the CRM.
• Every figure meant for a client is checked in Pennylane.
• Choose a Claude Team or Enterprise plan as soon as client data is involved.
• Start small: one use, one file you know, one written rule.

Sources

• Pennylane, Le MCP Pennylane est disponible pour les cabinets et les entreprises, updated on 13 October 2026.
• Pennylane, Pennylane MCP, Getting Started, technical documentation, accessed on 20 October 2026.
• Pennylane, Pennylane IA pour les cabinets comptables, accessed on 20 October 2026.
• Liberall Conseil, Connecter Claude à Pennylane : 5 cas d’usage pour votre cabinet comptable, April 2026.
• Anthropic, Updates to our consumer terms, 28 August 2025.
• Claude, Connecteurs personnalisés via MCP distant, help centre, accessed on 20 October 2026.