Features · 25 June 2026 · 6 min read

ISDOC: the invoice you never have to retype

What ISDOC is, how to open an .isdoc file and why it beats a PDF. Taxorio now imports ISDOC invoices and embeds one in every invoice it issues.

An invoice arrives by e-mail and you retype it into your records: supplier, IČO (the Czech business ID), amount, DPH (Czech VAT), supply date. Or you let an AI read it and then check whether it read everything correctly. Meanwhile a format in which invoices are readable by machines has existed here for almost twenty years — ISDOC. Taxorio now speaks it in both directions: it imports ISDOC invoices and embeds one in every invoice it issues.

What ISDOC is and why it matters to you

ISDOC (Information System Document) is the Czech national standard for electronic invoicing. It is not a picture of an invoice and not a PDF — it is machine-readable XML in which every value has its exact place: supplier, DIČ (tax ID), line items, tax bases, VAT rates, DUZP (date of taxable supply). You recognise the file by its extension:

Extension	What it contains
.isdoc	The invoice itself, as XML
.isdocx	A ZIP package — the invoice plus attachments, typically a PDF rendering

Most Czech accounting and invoicing programs can produce ISDOC — Pohoda, Money S3, iDoklad, Fakturoid and others. If a supplier invoices you from one of them, all you have to do is ask them to attach the ISDOC file as well. Several of those programs go further and embed it directly inside the PDF invoice as an attachment, which means you may already be receiving ISDOC today without knowing it.

Import: drop the file in and you are done

In Taxorio you upload an .isdoc or .isdocx file the same way as any other document — drag it into the expense inbox, or use the new-expense form, where an ISDOC file gets a Process document button. The difference shows up immediately:

The figures are read, not guessed. Supplier, IČO, DIČ, document number, issue date, DUZP, tax base, VAT and total come straight out of the XML, exactly as the supplier issued them. A typo or a misread amount is structurally impossible here.
It does not eat your AI scan allowance. Reading XML is cheap and deterministic, so ISDOC documents are not counted against the monthly AI scan limit. Import as many as you like.
Foreign currency converts itself. An invoice in euros is converted at the ČNB rate for the supply date, just like any other document in a foreign currency.
PDFs with an embedded ISDOC work too. Upload a PDF invoice that carries ISDOC as an attachment and Taxorio finds it and uses it instead of AI recognition. You get exact data, and again the scan is not counted against your limit.

💡 Tip: not sure whether your PDF invoices contain ISDOC? Just upload them as you always have. Taxorio looks for the attachment itself and takes the most accurate route available. There is nothing for you to decide.

When Taxorio asks you to look

Exact figures do not always mean an unambiguous tax treatment. Some documents are therefore marked as needing review, with the reason given — typically an invoice carrying several VAT rates, a foreign supplier (where the reverse-charge treatment has to be established), or an unusual rate on the document. A domestic reverse charge under § 92a of the Czech VAT Act is recognised from the document automatically.

⚠️ Taxorio deliberately refuses to import advance invoices from ISDOC. An advance invoice gives you neither an expense nor a VAT deduction — both come with the final tax document. Recording it would risk claiming the same thing twice. Such a file is rejected with a plain explanation of what to record instead.

Export: every Taxorio invoice is now a hybrid

The other direction matters just as much. Every PDF invoice Taxorio generates — on download, when sent by e-mail, and in exports — now carries an embedded ISDOC attachment. For the people you invoice this means:

A client running Pohoda, Money S3 or another accounting package loads your invoice in one click — no retyping and nothing to get wrong.
A client without accounting software notices nothing: the PDF looks and behaves exactly as before.
You configure nothing. It is simply there.

Electronic invoicing is not only a convenience — it is the direction the whole EU is moving in, with structured e-invoicing between businesses steadily becoming the norm rather than the exception. Getting used to machine-readable documents now means less to catch up on later.

How to put this into practice

Ask the suppliers who invoice you from accounting software to send ISDOC (or a PDF with ISDOC embedded).
Upload documents to Taxorio as you always have — drag them into Expenses.
ISDOC documents are read exactly, straight from the XML and without AI; everything else goes through the AI scan as before.
Send your own invoices from Taxorio — the ISDOC is already inside them.

In short

ISDOC is the most reliable way to move an invoice from one system into another: no retyping, no guessing, exact figures. Taxorio supports it both ways — it imports .isdoc, .isdocx and PDFs with an embedded ISDOC without counting them against the AI limit, and it embeds ISDOC in every invoice you issue. Try it on the next invoice you receive, and do your clients with accounting software a favour with the next one you send.

Taxorio scope: Taxorio provides invoicing and income/expense records for Czech sole traders. It is not full accounting or personalised tax advice. For an unsupported or unusual case, verify the treatment with a Czech accountant or tax adviser before filing.

Frequently asked questions

What is the ISDOC format and how do I open it?: ISDOC is the Czech national standard for electronic invoicing — machine-readable XML with the extension .isdoc (the invoice itself) or .isdocx (a ZIP package with attachments). Most Czech accounting programs open it. In Taxorio you simply drag it into Expenses and the values are read in automatically.
Does an ISDOC import count towards the monthly AI scan limit?: No. ISDOC is processed deterministically by reading the XML, so it is not counted against the AI scan limit. The same applies to PDF invoices that carry an embedded ISDOC attachment.
Can Taxorio issue ISDOC invoices as well?: Yes. Every PDF invoice generated in Taxorio — downloaded, e-mailed or exported — contains an embedded ISDOC attachment. A client with accounting software such as Pohoda or Money S3 loads it in one click; a client without one sees an ordinary PDF.
What happens if the ISDOC invoice is in a foreign currency?: Taxorio converts the amount at the ČNB rate for the date of taxable supply. If no rate is available, the document is flagged and you confirm it manually.