How to open a CII invoice XML and make it readable
Cross Industry Invoice, usually shortened to CII, is a structured XML syntax used by several European e-invoice profiles. A raw file can contain all the right data and still look like an unreadable wall of tags.
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If the document does not display as expected
Keep the original filename and check that the download is complete. Renaming XML, P7M or ASiC files to PDF does not convert them. If a signed container opens, check the type of its extracted payload: it may be an invoice, PDF or another format requiring its own reader.
For an invoice, compare the document identifier, supplier, currency, tax and total with the original fields. Report an unsupported format with its non-sensitive format/version details; avoid sending private documents unless you choose an appropriate support channel.
From difficult file to readable document.
- 01
Save the XML source
Download the complete invoice from the exchange system, portal or email. Keep its declared profile identifiers intact.
- 02
Open it with a CII-aware reader
Choose the file in EU Document Opener. Supported CII and EN 16931-related declarations are detected locally.
- 03
Compare important totals
Review the readable output and compare critical values with your business system. Preserve the XML for import and audit.
CII is used beneath several profile names
CII supplies an XML syntax for cross-industry business data. National and network profiles can constrain that syntax with their own identifiers and rules.
The same reader may therefore recognise CII inside workflows labelled Factur-X, ZUGFeRD or EN 16931, while each profile still has separate compliance requirements.
Readable does not mean fully validated
A viewer can map supported data and flag a detected profile. EU Document Opener also checks EN 16931 arithmetic for lines, VAT and totals, required fields and identifier check digits. Full validation can still require schema, semantic and country-specific business-rule checks; the app’s checks are not an official validation.
Why local parsing matters
CII invoices commonly contain confidential customer, supplier, payment and pricing data. A local workflow avoids handing those fields to a web converter just to see them laid out.
Authoritative references
Official specifications and public-sector documentation used to check the terminology in this guide.
Questions about this file type.
What does CII stand for?
Cross Industry Invoice, an XML message specification maintained through UN/CEFACT.
Is CII the same as UBL?
No. They are different XML syntaxes that can both be used to express European e-invoice data.
Can CII be part of Factur-X?
Yes. Factur-X hybrid invoices embed a CII-based XML invoice inside a PDF.