#NULL!

Excel #NULL! Error Applies to: Windows 7, Windows 10, Windows 11

What it means

A space was used instead of a comma between two ranges that don't actually intersect.

Also seen as: #NULL!

Quick fix steps

Check the formula for a space where a comma should be between two ranges, e.g. SUM(A1:A5 C1:C5) instead of SUM(A1:A5, C1:C5).
If you intended an intersection (the shared cells between two ranges), confirm the ranges genuinely overlap.

For the full step-by-step walkthrough, see Understanding Excel Formula Errors (#REF!, #VALUE!, and More).

Frequently Asked Questions

Is #NULL! a common error compared to others?

It's one of the less common formula errors, since it specifically relates to referencing the intersection of two ranges that don't actually overlap — usually caused by a specific typo in how a range reference is written.

What's the difference between a space and a colon in a formula reference?

A colon (like A1:A5) means a range, while a space between two ranges means "the intersection of these ranges" — using a space when you meant a colon or a comma is the typical cause of #NULL!.

Other error codes

#REF! — #REF! Error

A formula is pointing to a cell that no longer exists — usually because a row, column, or sheet it referenced was deleted.

#VALUE! — #VALUE! Error

The formula received the wrong type of data — commonly text where it expected a number.

#DIV/0! — #DIV/0! Error

The formula is dividing by zero or by an empty cell.

#N/A — #N/A Error

A lookup formula (VLOOKUP, MATCH, XLOOKUP, INDEX/MATCH) couldn't find a matching value.