999 File Type

- The quick facts

What are 999 files and how to open them

Are you having problems opening a 999 file or just wondering what they contain? We explain what these files are used for and show you software that we know can open or otherwise handle your 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.

How to open 999 files

Important: Different programs may use files with the 999 file extension for different purposes, so unless you are sure which format your 999 file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested 3 different 999 openers which you will find listed below.

Last updated: March 15, 2022

Suggest another file format using extension 999

While we know of one file format using the .999 file extension, there may be more. It is widespread that different programs use files with the same file extension for very different types of data. Please let us know if you are aware of a different kind of .999 file.

Various apps that use files with this extension

These apps are known to open certain types of 999 files. Remember, different programs may use 999 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Pro/ENGINEERPro/ENGINEERUser submitted
Creo Elements/ProCreo Elements/ProUser submitted
CreoCreoUser submitted