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ISNA Function

Excel 2007+

Summary

The Excel ISNA function specifically detects the #N/A error value, returning TRUE when a formula or cell contains #N/A and FALSE for all other values including other error types. This makes it essential for handling 'value not available' conditions common in lookup operations.

Syntax

ISNA(value)

Parameters

Parameter	Type	Required	Description
value	`Any`	Yes	Formula result, cell reference, or value to check for #N/A error

Using the ISNA Function

ISNA is your go-to function for specifically identifying #N/A errors, which frequently appear in lookup functions like VLOOKUP, HLOOKUP, and MATCH when data isn't found. Use it with IF statements to provide custom messages or alternative calculations when #N/A occurs.

Common ISNA Examples

#N/A Detection in VLOOKUP

=IF(ISNA(VLOOKUP(D2,A:B,2,FALSE)),"Not Found",VLOOKUP(D2,A:B,2,FALSE))

Checks if VLOOKUP returns #N/A and shows 'Not Found' instead

Data Cleanup Check

=IF(ISNA(A2),"Missing Data",A2*100)

Multiplies valid numbers by 100, shows 'Missing Data' for #N/A

Multiple Error Differentiation

=IF(ISNA(B2),"No Data",IF(ISERROR(B2),"Other Error",B2))

Distinguishes #N/A from other errors in column B

Frequently Asked Questions

FALSE. ISNA only returns TRUE for #N/A errors specifically.

Use ISNA when you specifically need to catch #N/A errors (common in lookups). Use ISERROR for any error type.

Yes, ISNA works perfectly with dynamic arrays and works across entire ranges.

Common Errors and Solutions

ISNA("#N/A") returns FALSE

Cause: Text strings resembling #N/A are treated as text, not errors

Solution: Test actual error values from formulas, not typed error text

Unexpected TRUE results

Cause: Formula produces legitimate #N/A error

Solution: Fix source data or formula logic causing #N/A

Notes

ISNA returns TRUE only for #N/A error value
Does NOT detect: #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, #NULL!
Perfect companion for VLOOKUP, XLOOKUP, INDEX/MATCH
Text 'N/A' or '#N/A' returns FALSE
Available since Excel 2000

Compatibility

Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365, Excel 2000+

Not available in:

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+