# A to Z of Excel Functions: the ISERROR Function

10 May 2021

*Welcome back to our regular A to Z of Excel Functions blog. Today we look at the ISERROR function. *

**The ISERROR function**

At the time of writing, there are 12 **IS** functions, *i.e.* functions that give rise to a TRUE or FALSE value depending upon whether a certain condition is met:

**ISBLANK(reference):**checks whether the**reference**is to an empty cell**ISERR(value):**checks whether the**value**is an error (*e.g. #REF!, #DIV/0!, #NULL!*). This check specifically excludes*#N/A***ISERROR(value):**checks whether the**value**is an error (*e.g. #REF!, #DIV/0!, #NULL!*). This is probably the most commonly used of these functions in financial modelling**ISEVEN(number):**checks to see if the**number**is even**ISFORMULA(reference):**checks to see whether the**reference**is to a cell containing a formula**ISLOGICAL(value):**checks to see whether the**value**is a logical (TRUE or FALSE) value**ISNA(value):**checks to see whether the**value**is*#N/A*. This gives us the rather crude identity**ISERR + ISNA = ISERROR****ISNONTEXT(value):**checks whether the**value**is not text (*N.B.*blank cells are not text)**ISNUMBER(value):**checks whether the**value**is a number**ISODD(number):**checks to see if the**number**is odd. Personally, I find the number 46 very odd, but Excel doesn’t**ISREF(value):**checks whether the**value**is a reference**ISTEXT(value):**checks whether the**value**is text.

As stated above, the **ISERROR **function checks whether the value is an error and returns either TRUE or FALSE accordingly. This specifically checks for all types of *prima facie *errors (*e.g. #VALUE!*, *#REF!*, *#NAME?* and the relatively new ones, *#CALC!*, *#SPILL!* and *#FIELD!*) including *#N/A. *It has the following syntax:

**ISERROR(value)**

The **ISERROR** function has the following argument:

**value:**this is required and represents the**value**for which you wish to determine whether it is an error.

It should be further noted that:

- technically,
*#N/A*is not an error: it is a special value that you may manually enter into a cell to indicate that the necessary value is not available yet. If you wish to exclude this, use**ISERR**instead *#####*is also not technically an error: this denotes that the column is not wide enough to display all the characters required in the current cell width- The #
*CALC!*and*#SPILL!*errors are only recognised in versions of Excel that support dynamic arrays; otherwise, these are treated as text strings and therefore are not considered errors **IFERROR**and**IF(ISERROR)**are different;**IFERROR**calculates the expression if there is no error; you may choose to calculate a different expression if there is no error with**IF(ISERROR)**,*e.g.***IFERROR(5/2,0)**= 2.5 but**IF(ISERROR(5/2),0,1)**= 1.

Please see my example below:

*We’ll continue our A to Z of Excel Functions soon. Keep checking back – there’s a new blog post every business day.*

*A full page of the function articles can be found here. *