How to open ASiC-E and ASiC-S signature containers
An ASiC file is an archive designed to keep one or more documents together with electronic signatures or time assertions. Renaming it to ZIP may expose files, but it does not explain which entries belong together or make the signature authoritative.
Updated
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.
Try an unsigned ASiC-E extraction example
Read the walkthrough transcript · Download the 24-second video
Download the fictional ASiC-E container. It contains a fictional FatturaPA invoice and a text note. It is deliberately unsigned: this demonstrates file extraction, not signature validation or legal validity.
- Save the container to Files or Finder, then open it with EUdoc.
- Expect two extracted files:
fattura-dimostrativa.xmlandreadme.txt. - Inspect the invoice: 100 euros net, 22 euros tax and 122 euros total. Compare the original XML and original note.
- Keep the container and its originals. PDF export and professional extraction/sharing require Pro.
Tested on 9 September 2026 with EUdoc’s production document library: one invoice detected, two extracted payloads identical byte for byte to the originals. An extracted file is not proof that a signature is valid. For a signed document, use an appropriate validation service when verification is required.
From difficult file to readable document.
- 01
Keep the original ASiC file
Save the .asice, .asics, .sce or .scs container unchanged. The complete archive may be required for later verification or evidence.
- 02
Inspect the archive locally
Choose the file in EU Document Opener. The app checks the supported container structure and lists safe document entries without uploading the archive.
- 03
Extract only what you need
Preview a supported payload or save a separate copy. Preserve the source container even after extracting a PDF, XML invoice or other document.
ASiC-E and ASiC-S are containers, not document formats
ASiC-S normally associates a signature with a single data object, while ASiC-E can hold several data objects and signature material. The file you want to read may therefore be nested inside the container.
The visible extension can vary between systems. What matters is the archive structure and its signature metadata, not merely the filename.
Why ordinary ZIP extraction is incomplete
An archive utility can sometimes unpack an ASiC file, but it does not necessarily show the relationship between the payload and signature entries. It may also hide malformed or unsafe paths that a defensive document workflow should reject.
EU Document Opener treats extraction as document inspection. Successful extraction alone does not prove signer identity, certificate status or legal validity. Separately, the app checks the CAdES or XAdES signatures in supported ASiC-E, ASiC-S, BDOC and EDOC containers offline against the EU trusted lists included in the app and shows each result; that check is not an official validation either.
Preserve the evidence-bearing original
An extracted document is useful for reading, but it is no longer the complete signed container. Keep the original ASiC file for any authoritative validation, regulated retention or dispute process that applies to you.
Authoritative references
Official specifications and public-sector documentation used to check the terminology in this guide.
Questions about this file type.
Is an ASiC file just a ZIP file?
It uses a ZIP-based container structure, but ASiC adds rules for packaged data and signature material. Treat the original as a signed container.
Can ASiC contain several documents?
ASiC-E may contain multiple data objects. ASiC-S is designed around a single associated data object.
Does extraction validate the signature?
No. Extraction makes supported payloads readable. The app runs a separate offline signature check against the EU trusted lists bundled with it; revocation is checked only when the signature includes revocation data. That check helps you spot problems but is not an official validation.