DDD file – what it is and how to open it
DDD is the most popular extension for files with data downloaded from a driver card or a digital tachograph. It is a binary file with a digital signature – you cannot open it in Word or Excel, but you can read it in your browser in DDDStart.
Where the DDD file comes from
The file is created when the data is downloaded: from the driver card with a card reader, or from the tachograph with a download key or a remote download device. The file structure is defined in Annex IC to Implementing Regulation (EU) 2016/799 and is the same for all tachograph manufacturers.
Other extensions for the same data
.DDD– the most common, used by most programs and devices,.ESM– files from some keys and programs (e.g. older Siemens VDO tools),.C1Bi.V1B– card and vehicle in French naming,.TGD– files from Spanish tools.
DDDStart recognises the content regardless of the extension – what counts is the file structure, not its name.
How to open a DDD file
- Create a DDDStart account and check the available analysis packages.
- Drag the DDD file onto the “Files” page.
- After the file is processed you will see the driver or vehicle, the daily chart, infringements and events. You can download the report as PDF and copy the infringements table in CSV format.
Can a DDD file be edited?
No. The data in the file is digitally signed by the card or tachograph, and changing even one byte invalidates the signature. That is why the DDD file is evidence during an inspection and the originals must be kept – DDDStart keeps only the 5 most recently sent files, each for up to 3 months after its last use, and makes reports available for up to 12 months from the analysis, with the option of earlier deletion.
Questions and answers
Can I open a DDD file on my phone?
Yes. DDDStart works in the phone's browser – just choose the file from the phone's storage or from e-mail.
My file does not open – what should I do?
Make sure it is a file from a card or tachograph, not a PDF report. If the file is correct but still cannot be read, it goes to diagnostics and we analyse it manually.
Updated: 12 October 2026 · Prepared by the DDDStart team (AMK VISION sp. z o.o.). For information only; this is not legal advice.