If you are using a formula with approximate match (range_lookup argument set to TRUE or omitted), your Vlookup formula might return the #N/A error in two cases: If you are searching with exact match (range_lookup argument set to FALSE) and the exact value is not found, the #N/A error is also returned.
See more details on how to properly use exact and approximate match VLOOKUP formulas.
Below you will find solutions for a few common scenarios when VLOOKUP fails.
The VLOOKUP function does not distinguish case and teats lowercase and UPPERCASE characters as identical.
The most obvious indications of numbers being formatted as text are shown in the screenshot below.