A sole proprietor books receipts with Claude Code and approves each

A one-person business built a Claude Code skill that reads receipts from its Fiken inbox and proposes an account for each one from past bookings. The owner confirms every proposal before anything is booked.

Tools mentioned

Source: Personal blogAug 2026

The task

Receipts are forwarded to the Fiken inbox as soon as they arrive, and they wait there. Once a month the owner spent an evening booking them by hand: find the supplier, choose the account, choose the VAT code, upload the PDF, move on to the next one. Most of the form is copied from the PDF. Only the supplier and the cost account need a decision.

What they did

The owner wrote a Claude Code skill that works through the Fiken API, with access limited to one company. It runs in nine steps. It finds unused items in the Fiken inbox and asks which one to handle when there are several. It downloads the PDF and reads it directly, taking supplier, invoice number, date, currency, and net and gross amounts, with no separate text recognition service. It looks the supplier up in the contact register and fetches the last five purchases from that supplier. When it finds a match, it proposes the same account and VAT type as last time. It shows the proposal and waits. After a yes, it posts the purchase, attaches the PDF, confirms the result, and cleans up. According to the source, the proposal is a lookup of earlier bookings and involves no machine learning. A new supplier needs a decision once, and later receipts from that supplier reuse it.

What the source reports

According to the author, the 98 receipts from eight months came from 19 suppliers, and 95 percent of them came from a supplier the owner had already booked before. According to the author, booking by hand took a little over two hours a month, about 13 receipts at around ten minutes each, and with the skill a month of receipts takes a few minutes of confirmations.

Where the approval sits

The owner approves every receipt. The skill shows its proposed account and VAT code and waits for a yes before it posts anything. Booking and attaching the PDF happen only after that confirmation. The author says this is not a system that keeps the books unattended. In essence, the proposal step is the only one where the skill decides something, and the confirmation is the only step that needs the owner.

Worth knowing

This is one person's account of a personal setup. It ends with an offer to build similar automation for other businesses. The skill is built for a sole proprietorship that is not VAT-registered and pays with private cards. According to the source, a VAT-registered business would need a different VAT type on almost every line, and a business paying from a company account would need a different payment account. The source also says Fiken API access is a paid add-on at 99 kroner a month on top of a base price of 219 kroner. In Germany, section 147 of the Abgabenordnung requires booking receipts to be kept for eight years. This entry describes one setup and is not tax advice; consult a qualified tax adviser about your own booking rules.

Source: Personal blog · Aug 2026

Drafted with AI assistance and checked automatically. A person is responsible for the collection. How these entries are made

Prompt for your agent

Expense list for your tax advisor from a month of receipts

Turn a month of receipts into an expense table with net amounts, VAT and account numbers that your tax advisor can check.

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