VBA UDF returning #VALUE!

Question

So I have a pretty simple UDF written in visual basic for use in excel. It calculates your approx. taxes. Lets say I use it as such:

=Taxes(I23-I18,I24-I20,\         


        

Answer 1

Your UDF's look OK, apart from using Currency data types (probably should be using doubles or variants since that is what Excel uses).
The usual reason for getting #Value with a UDF is that one of the input arguments cannot be converted to the correct type. If your input cells do not contain numeric values when the workbook opens you would get #Value.
This might be caused by calculation sequence problems resulting in one of the upstream precedent cells being uncalculated the first time the function is called.
Try declaring the input parameters as variant rather than currency and add some temporary debug.print statements to show the input parameters in the Immediate window.