Having problems opening a 999 file?

We have programs that can open or convert your 999 files.

Opening 999 files

Did your computer fail to open a 999 file? We explain what 999 files are and recommend software that we know can open or convert your 999 files.

What is a 999 file?

The .999 file extension is most commonly used by Sage business software applications. The 999 files contain backup files that have been created with a Sage program.

The .999 file extension is also used for multi-pass security files.

Try a universal file viewer

Try a universal file viewer like Free File Viewer. It can open over 200 different types of files - and most likely yours too. Download Free File Viewer here.

About File Extension 999

File.org aims to be the go-to resource for file type- and related software information. We spend countless hours researching various file formats and software that can open, convert, create or otherwise work with those files.

If you have additional information about the 999 file format or software that uses files with the 999 suffix, please do get in touch - we would love hearing from you.