Sometimes you will have a formula in a series of cells and in some of those cells there is an error and the cell displays #N/A. #N/A indicates "Not Applicable" or "Not Available". #N/A can come in for a variety of reasons. In my case, I encountered it while using the VLOOKUP formula where the value could not be referenced.

Now in another cell I wanted to check if this cell had a proper value before proceeding with further operation. Suppose you have #N/A coming in from a formula in Cell C1, and you want to check if it has #N/A in another cell D1, then in cell D1, you can use the following formula:

=ISNA(C1)

or

\=ISERROR(C1)

Both these formulas return a TRUE or FALSE. WHile ISNA is specifically to catch #N/A error, ISERROR can be used to catch all kinds of errors such as #N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, or #NULL!

I hope this helps!