Fix a conditional formatting formula that is not firing.

What this page gives you

• A corrected conditional-formatting formula for the rule you are trying to apply.
• A plain-English read of the TRUE/FALSE logic, first-row reference, and locked columns or rows.
• Checks for apply-to range, formula errors, cross-sheet references, and rule precedence.

When to use it

Use this page when a custom conditional formatting formula highlights the wrong cells, does not fire, applies to every row, shifts references incorrectly, or behaves differently in the rule dialog than it does in a normal worksheet cell.

Do not use it as a full-file review or as proof that every formatting rule is correct. Start with one rule, verify the apply-to range, and test the corrected formula on a small section before applying it broadly.

Worked example

The apply-to range is A2:C100. Due dates are in column B and status is in column C. Highlight each row when the due date is before today and the status is not Done.

=AND($B2<TODAY(),$C2<>"Done")

The formula returns TRUE only when both checks pass. Columns B and C stay locked while the row number moves from row 2 downward, so each row checks its own due date and status.