How to open .123 file extension?

If you cannot open a new file that has been saved in the .123 format you need to download the appropriate software. The manufacturer of .123 files is IBM; .123 files belong to the Spreadsheet Files category. After downloading the application from the list available on our website just run an unknown file, and as the default set the newly installed application supporting the .123 files. Activities performed in the order described should solve the problems with all the files in the .123 format.