Highlighting rows where Column A data exists in Column B

You can use Excel's built-in functions and conditional formatting to highlight rows where the data in **Column A** exists in **Column B**. Here's how:

### Steps to Highlight Matches Between Column A and Column B:

#### 1. **Add a Helper Column (Optional)**
   Use a formula in a helper column to check if each value in **Column A** exists in **Column B**:
   - In cell `C1` (assuming your data starts from row 1), enter the formula:
     ```
     =IF(ISNUMBER(MATCH(A1,B:B,0)),"Match","No Match")
     ```
   - Drag the formula down to apply it to the entire column.

#### 2. **Apply Conditional Formatting**
   - Select all the cells in **Column A** (e.g., `A1:A100`).
   - Go to **Home > Conditional Formatting > New Rule**.
   - Choose **Use a formula to determine which cells to format**.
   - Enter the following formula:
     ```
     =ISNUMBER(MATCH(A1,B:B,0))
     ```
   - Click on the **Format** button, go to the **Fill** tab, and choose a color (e.g., green).
   - Click **OK** to apply the rule.

#### 3. **Explanation of the Formula**
   - `MATCH(A1,B:B,0)`: Checks if the value in Column A exists in Column B.
   - `ISNUMBER()`: Returns `TRUE` if `MATCH` finds a match, indicating that the value exists in Column B.
   - The conditional formatting highlights rows where `MATCH` succeeds.

#### 4. **Result**
   - Rows in Column A that have a corresponding match in Column B will be highlighted with the color you selected.

If you need further assistance or have additional requirements, let me know!