Set the lower and upper boundaries of the condition to 24000999, respectively.

Use the next drop-down list in the rule description to choose Not Between.

The left portion of the rule description should automatically be set to Cell Value.

In the Select a Rule Type area at the top of the dialog box, choose Format Only Cells That Contain.

Excel displays the New Formatting Rule dialog box. Excel displays a palette of options related to conditional formatting.

With the Home tab of the ruler displayed, click the Conditional Formatting option in the Styles group.

These steps will even work if the phone numbers are numeric, but you may want to use a different approach if the phone numbers were entered as numbers. The formatting you specified in step 7 should now appear in the preview area for the rule. Click OK to dismiss the Format Cells dialog box.Set the formatting options to highlight the errant phone numbers, as desired.Click Format to display the Format Cells dialog box.In the Format Values Where This Formula Is True box, enter the following formula, replacing A3 with the address of the active cell selected in step 1:.In the Select a Rule Type area at the top of the dialog box, choose Use a Formula to Determine Which Cells to Format.With the Home tab of the ribbon displayed, click the Conditional Formatting option in the Styles group.(For the sake of this example, I assume that the first cell you select is A3.) Select the cells containing the phone numbers.If your phone numbers are text entries, then use these steps to apply the desired conditional formatting: If you format the cells as phone numbers (Format Cells dialog box | Number tab | Special | Phone Number), then the phone number is considered a number and formatted for display by Excel. If you enter a phone number with dashes, periods, parentheses, or other non-numeric characters, then the phone number is considered a text entry. The way that you do this depends on whether your phone numbers are stored as text or as formatted numbers. You might want to highlight all the phone numbers in the list that do not begin with 240, and therefore would be long distance.

For instance, for your area, only phone numbers in the 240 exchange (those beginning with 240) may be local calls. If you use Excel to store a list of phone numbers, you may want a way to determine if any of the phone numbers in your list are outside of a specific range.

Conditional formatting excel 2016 text