How to Catch Errors Except #N/A with ISERR in Excel

ISERR flags every error except #N/A — so genuine formula faults stand out from items that simply aren’t found yet.

You will learn to

• Flag real formula faults while ignoring #N/A
• Count the faults in a column
• Count the #N/A cells using the difference between ISERROR and ISERR

How it works

ISERR(value) returns TRUE for #DIV/0!, #VALUE!, #REF!, #NAME?, #NUM! and #NULL! — every error except #N/A. In many sheets #N/A is expected (a lookup that has no match yet), while the other errors mean a formula is genuinely broken. ISERR lets you flag only the broken ones.

Compare it with ISERROR, which includes #N/A. Subtracting one from the other isolates the #N/A cells: =SUMPRODUCT(ISERROR(D2:D8)-ISERR(D2:D8)) counts only the "not found" errors.

=ISERR(D2)