I received file with extension .ddoc instead of .xls or .xlsx.

So - what are .ddoc files? Are they even related to Microsoft Excel?


You're expecting a .xls or .xlsx file? That is an Excel 95/2000/XP file, or an Excel 2007/2010 file?

Google says .ddoc files are either: (1) DigiDoc Digital signature files (2) Digital Mars C, C++ or D files. Is it possible the sender mis-typed .ddoc in a Save As... command, when they might better have left Windows to add in the extension?

If you've not already, try changing the file extension to .xls (and/or .xlsx, .doc, or .docx ) then see if your recent version of Excel (or Word) opens it.

| improve this answer | |

There is an Estonian (and possibly neighbouring countries) digitally signed document format called DigiDoc that has a .ddoc extension. You can open such documents on this site:


Use Add Document to upload the doc for a 30 minute anonymous session. You can verify the signature, download and save the PDF, and see a Confirmation page verifying the document validity.

The format may be used for communicating official information with the Estonian authorities, and, in conjunction with an Estonian Smart ID card or Mobile ID if you need to sign your own documents.

| improve this answer | |

Could also be a MacDraw graphic file, according to a couple of File Extensions sites.


P.S. I built that website

| improve this answer | |

Its a digital document format which is assigned digitally by user. More information at: http://id.ee/?lang=en&id=

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.