Microsoft® Office Excel 2003 Inside Out

Making Your Custom Functions Available Anywhere

To use a custom function, the workbook containing the module in which you create the function must be open. If that workbook is not open, you get a #NAME? error when you try to use the function. Even if the workbook is open, if you use the function in a different workbook, you must precede the function name with the name of the workbook in which the function resides. For example, if you create a function called Discount in a workbook called Personal.xls, and you call that function from another workbook, you must write =personal.xls!Discount(), not simply =Discount().

You can save yourself some keystrokes (and possible typing errors) by selecting your custom functions from the Insert Function dialog ...