The Excel ISNA function is designed to return a custom error text “TRUE” when a cell is found to contain the #N/A error while a different custom text “FALSE” where there is another error type. The Excel ISNA function can be used together with IF function to display a more friendly (custom) error message where there is an error instead of the #N/A appearing
Purpose of the Excel ISNA function
Used to test a cell for #N/A error
Return Value for the Excel ISNA function
A logical value of TRUE when the cell contains the #N/A or FALSE when it’s a different error type that is present.
Logical Arguments applied in the Excel ISNA Function
- Value: This is the value within a cell to check for if it contains #N/A error
Figure 1: Example showing how to use the Excel ISNA function to return a custom text ‘TRUE’ when a cell contains the #N/A error
The formula used here is:
If F5 contains a #N/A error, the formula below will return a TRUE value:
Usage Notes about the Excel ISNA Function
- The Excel ISNA function is usually used to check for #N/A error that occurs within a cell.
- The value checked for is usually provided as a cell reference.
- If you want to purposely impose the #N/A error to a formula, you can use the NA function and when tested with the ISNA function below, a TRUE value will return
Notes to observe when using the Excel ISNA Function
- ISNA is a member of the functions group known as the “IS functions”, which are usually used for testing the result of formula for any error.
- When using Excel 2007+, the Excel IFERROR function can give a simpler and less superfluous checking for errors.
- With Excel 2013 and higher versions, the Excel ISNA function can be used to spot and manage #N/A errors in particular.