Three months ago I made a video about doing accounting with Claude. 18,000 of you watched it, and the same question kept coming back in the comments: "Do I have to install VS Code for this? Do I have to touch a terminal?" That's where most accountants stop. Not at the AI part, at the developer tooling in front of it.

So this time: no terminal, no code editor, nothing that looks like programming. Just Claude Cowork on the desktop, hand-clicking a real month of accounting work.

The setup

A small coffee roaster, six months of general ledgers: sales with VAT, EU purchases under reverse charge, payroll, a bank loan, depreciation, the boring stuff that shows up in a real set of books. And in the July ledger I planted three real errors, the kind everyone has posted at some point and not noticed. I didn't tell Claude they existed.

The key difference with Cowork versus regular chat: you point it at a folder on your computer. No uploading files, no downloading outputs, it works directly where your files already live.

Demo 1: Closing the months

First task: take the January–June general ledger and build a monthly P&L and balance sheet as a new Excel file, with formulas, not hard-coded numbers, so every figure traces back to the ledger.

Five minutes later there was a new file in the folder: revenue split by account with live SUM formulas across the months, wages, depreciation, finance costs, net result, and a balance sheet with built-in checks. It even flagged findings on its own, including that no VAT had ever been paid to the tax authority. That's the kind of thing you don't think about while staring at profits... until the State Revenue Service asks where the money is.

Why not just use chat?

Regular chat is a conversation: you ask, it answers, you copy the text somewhere, and next month you do the whole dance again. Cowork is a delegation. Three practical differences:

  • It works with your files where they live, opens the ledger, writes the P&L, and the file is just there when it's done.
  • It works in steps on its own, build, check, notice something is off, go back and verify, while you do something else.
  • It can run on a schedule, month-end close on the first working day, every month, without you starting it.

Demo 2: The error hunt

I gave it the July ledger and asked whether it was safe to close the month. The totals matched, modern accounting software won't let a debit post without a credit, so you can't spot these mistakes from the totals.

Claude came back: "Don't close July yet." It found all three planted errors:

  • Loan interest overstated, it recalculated the amortization schedule itself and caught that July's posted interest didn't match the actual split of principal and interest.
  • A supplier invoice booked twice, a classic human-factor duplicate.
  • Wrong VAT on a sales invoice, the ledger implied a 32% rate; the correct Latvian rate is 21%. It recalculated what the VAT should have been, to the euro.

Demo 3: Invoices with no data entry

Last, I pointed it at a folder of 10 July invoices (incoming and outgoing) and asked it to build a register, date, document number, supplier, amount, and tell me which ones weren't booked correctly in the ledger. In a couple of minutes: all 10 documents matched to the register, four clean, three flagged, the same three errors, this time confirmed against the source PDFs.

What this means

It doesn't replace the accountant. It doesn't know which judgment call your client would want, or that a particular loan is from the parent company and shouldn't sit in that ratio. What it replaces is the two hours of mechanical work in front of the judgment call.

And the real game-changer isn't even Excel, it's connecting AI directly to the accounting system, so there's nothing to export at all: tie bank statement transactions to documents, check the month, calculate the VAT to pay. We've built this for over 130 companies.

One serious note: everything above ran on a demo company built for the video. Before you point this at real client files, understand your own data rules, that's on you, not on the tool.