Key points at a glance
- Modern AI models usually read the supplier, date, amount, currency and VAT from photos and PDFs reliably - but not flawlessly.
- Before you file your VAT return, check the amounts, VAT rate and date in particular. You remain responsible for your bookkeeping.
- To be read, the receipt is sent to the AI provider. This is processing by a processor (Auftragsbearbeitung), often with disclosure abroad (Art. 9 and 16 of the Federal Act on Data Protection, FADP).
- Always keep the original file - it is the actual receipt, not the extracted values.
How AI reads a receipt
You upload a photo or a PDF, or forward an invoice by email. The software sends the file to an AI model, such as Claude from Anthropic or ChatGPT from OpenAI, along with precise instructions: which fields to look for and in what format to return them. The model "reads" the receipt much like a person would - even a till receipt photographed at an angle or a multi-page PDF - and returns structured values that go straight into the form.
Unlike conventional text recognition (OCR), AI also understands context: it recognizes which amount is the total and which is only a subtotal, and it assigns the receipt to a category such as "office supplies" or "software".
What works reliably - and what you must check
| Field | In practice | What to watch for |
|---|---|---|
| Supplier | usually correct | Spelling, so the same supplier doesn't appear twice |
| Date | usually correct | Invoice date rather than delivery or due date; day and month mixed up |
| Amount | usually correct | Total including VAT; discounts, tips, partial payments |
| VAT | tricky | Only accept it if the receipt shows it; check carefully if there are several rates |
| Category | suggestion | Does it fit your bookkeeping? Change it if needed |
VAT is especially important: in practice, you can only deduct input tax if you can prove the VAT you paid - which normally means it is shown on the receipt (Art. 28 para. 4 of the Value Added Tax Act, VATA). That's why a good solution never estimates a VAT amount; it leaves the field empty if the amount isn't on the receipt.
Typical sources of error
- Poor photos: blurred, cut off or shadowed. Photograph the whole receipt lying flat and in good light.
- Thermal paper: till receipts fade over time. Record them right away.
- Several receipts in one image: Upload one file per receipt.
- Foreign currencies: The amount must be converted into francs at the correct rate.
- Duplicate receipts: the same invoice as a photo and as an email attachment. Keep an eye out for duplicates.
Example: a photographer with lots of small receipts
Marco works as a self-employed photographer and collects around 40 receipts a month: memory cards, train tickets, software subscriptions, repairs. He used to type everything in at the end of each quarter. Now he photographs every receipt right after buying something and forwards emailed invoices to his receipts mailbox. Once a week, he goes through the extracted values and corrects the two or three cases where something is off - usually a blurry photo or a till receipt with two VAT rates.
Data protection: what to consider
To be read, the receipt is sent to the AI provider. Receipts often contain personal data - your name, customers' names on travel expense receipts, details on medical bills. For you, this means:
- The AI provider processes the data on your behalf. You must make sure it only processes the data in the way you yourself would be allowed to, and that it ensures data security (processing by a processor, Art. 9 FADP).
- The major providers are based in the US. Disclosure abroad is permitted if the level of data protection there is adequate (Art. 16 FADP). For the US, this has applied since September 15, 2024, to companies certified under the Swiss-US Data Privacy Framework (the official list of the US Department of Commerce shows whether a provider is certified); otherwise you need standard contractual clauses, for example.
- According to Anthropic and OpenAI, data sent through their programming interfaces (APIs) is not used to train their models by default. Check your provider's current terms and mention the data transfer in your privacy policy.
You'll find more on this topic in the article Data protection in a small business.
Your own AI access or built into the software?
Some programs include AI use in the subscription price; others work with your own account at the AI provider. With your own account, you have a direct contract with the provider, see the costs clearly on its bill and can choose the provider yourself. In return, you have to set up an account once and enter an API key in the software.
How it works in Easly
Easly reads receipts using your own AI account - and shows you the result so you can check it:
- Your provider, your bill: You enter an API key from Anthropic (Claude) or OpenAI (ChatGPT). The provider bills you directly. Without an AI account, you record receipts by hand.
- Many formats: photos (JPG, PNG, WebP), PDF, but also emails, Word and Excel files. You forward invoices to a mailbox; Easly picks them up via IMAP or Microsoft 365 - only from senders you have approved.
- Extracted fields: supplier, description, category, date, amount, currency and - only if shown on the receipt - VAT rate and VAT amount. If the AI is unsure about a value, it adds a note.
- Check against the original: On each receipt, you see the original file next to the fields and can correct them as needed. Receipts that are still being processed or couldn't be read appear on the dashboard under "Expenses to review".
- Duplicates are flagged and shown side by side with the likely original. Nothing is deleted; the original file stays stored unchanged.
- Foreign currencies: Easly converts amounts into francs at the daily VAT exchange rate of the Federal Tax Administration FTA (ESTV) (rates from the FOCBS/BAZG; page in German) on the receipt date - on weekends and public holidays at the most recently published rate, as the FTA specifies.
- Hardware and licenses: The AI recognizes them on the invoice; one click adds them to your inventory.
Frequently asked questions
How accurately does the AI read receipts?
With clearly legible receipts, the supplier, date and amount are usually right. Errors mainly occur with blurry photos, faded till receipts and receipts with several VAT rates. So check the values before you file your VAT return.
Can I keep just the extracted values?
No. The receipt itself must be kept for 10 years (Art. 958f of the Swiss Code of Obligations, CO) - electronic storage is allowed as long as the original file remains complete, unaltered and readable. The extracted values are just an aid for your bookkeeping.
Are my receipts used to train the AI?
According to Anthropic and OpenAI, data sent through their APIs is not used for training by default. Terms can change - check them with your provider.
Does Easly also work without AI?
Yes. Without an AI account, you upload the receipt and fill in the supplier, date, amount and VAT by hand. Everything else works the same.
Information as of: see above. Sources: Federal Act on Data Protection (Art. 9 and 16 FADP) with the Data Protection Ordinance (Annex 1 DPO), Swiss Code of Obligations (Art. 958f CO), AI providers' information on API use. This article is not a substitute for legal or accounting advice.