Error: #N/A (Value Not Available)
The Common Causes
The #N/A error is actually useful—it tells you the lookup value doesn't exist in the table array. However, often it SHOULD be there.
1. Text vs. Number Mismatch
The most common cause. Your lookup value is a number (123), but your table array has it stored as text ("123"). You'll see a green triangle in the corner of the cell. Convert them to numbers.
2. Invisible Spaces
Use the =LEN() function to check string length. "Apple" is 5 chars. "Apple " is 6. VLOOKUP requires an exact match if the last argument is FALSE (0). Use =TRIM() to clean your data.
3. Approximate Match Danger
Did you forget the 4th argument? =VLOOKUP(val, range, col) defaults to TRUE (Approximate Match). Always use =VLOOKUP(val, range, col, FALSE) or 0 for exact matches.