The File Extensions Database

.123 File Extension

  • Developer by: IBM
  • Category: Spreadsheet Files
  • Format: Binary

What is an .123 file?

.123 is Lotus 1-2-3 Spreadsheet

Spreadsheet created by Lotus 1-2-3, part of IBM Lotus SmartSuite; organizes data in rows and columns; functions can be applied to the data in various cells, which can automatically populate the data in other cells.

Lotus 1-2-3 was first developed by Lotus Development Corporation, which was bought by IBM in 1995. The "1-2-3" refers to the program's three main capabilities: 1) spreadsheet functions, 2) creating charts and graphs, and 3) basic database operations.

Programs that open Lotus 1-2-3 Spreadsheet
IBM Collaboration Solutions
Corel Quattro Pro X9
Apache OpenOffice
Planamesa NeoOffice
Apache OpenOffice
Apache OpenOffice
File Type 2 PCB123 Circuit Board Design
Developer by: Sunstone Circuits Category: CAD Files

Printed circuit board (PCB) layout created with PCB123, a PCB design program; contains a circuit board design, which can include multiple components; supports 2, 4, and 6-layer circuit boards with soldermask and silkscreen options.

Completed PCB123 designs can be sent to Sunstone Circuits for manufacturing. Assembly quotes are provided within the program.

Programs that open PCB123 Circuit Board Design
Sunstone Circuits PCB123

How to solve problems with 123 files

  • Associate the 123 file extension with the correct application. On :
    Windows: Right click on any 123 file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.123 files". Mac: Right click (or Ctrl-click) the 123 file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .123 is Lotus 1-2-3 Spreadsheet. Because only the current version supports the latest 123 file format. Search, therefore, e.g. on the IBM manufacturer website after an available .123 is Lotus 1-2-3 Spreadsheet update.
  • To make sure that your 123 file is not corrupted or virus-infected, get the file again and scan it with antivirus software.