Adding Area Codes to Phone Numbers

Ron has a worksheet that has a column of phone numbers. Some are seven-digit numbers, as in 123-4567, with the 727 area code assumed. Others have area codes included, as in (890) 123-4567. Ron wants to have every phone number in the latter format and wonders about the best way to detect the shorter phone numbers and add the missing (727) to those numbers.

The best way to go about this is going to depend on the nature of your data. You see, it is possible for the data to be text or numeric. This is possible because Excel provides a special cell format that allows numbers like 8015551212 to be displayed as (801) 555-1212. You can tell whether your data is numeric or text by comparing what you see in the cell with what is shown in the formula bar. (See Figure 1.)

Figure 1. Figuring out if a phone number is text or numeric.

If your data happens to be numeric, you can easily add the proper area code by using a formula such as this:

=IF(A1<=9999999,7270000000+A1, A1)

The result will add the proper area code, but you will still need to format the cell containing this formula with the special Phone Number format.

If the data is textual, then you can simply use a formula to check the length of the cell and then add the area code, as needed:

=IF(LEN(A1) = 8, "(727) " & A1, A1)

Thus, if the phone number is 555-1212 (8 characters long), then this formula returns (727) 555-1212. Of course, it is possible that the phone number may have some extra spaces around it; this often happens if phone numbers are pasted into a worksheet from a different source. In that case, just include the TRIM function in your formula:

=IF(LEN(TRIM(A1)) = 8, "(727) " & TRIM(A1), TRIM(A1))

There's another formula you may find very helpful for adding the area code, and it is shorter than those we've seen so far:

=RIGHT("(727) " & TRIM(A1), 14)

This formula adds the area code to all the cells and then just takes the rightmost 14 characters of the result.

Things become a bit stickier if your data has some phone numbers that are numeric and some that are textual. In that case, you can still put together a formula, but it becomes longer:

=IF(LEN(TRIM(A1)) > 9, TRIM(A1),
IF(LEN(TRIM(A1)) = 8, "(724) " & TRIM(A1),
IF(LEN(TRIM(A1)) = 7, 7240000000+A1, "Undetermined")))

Remember that this is a single formula. It keys off the length of whatever is in cell A1. If the length is over 9 characters, then the phone number is assumed correct. If the length is exactly 8, then the formula assumes it is a "short text" version of the phone number, such as 555-1212, and adds the area code to the beginning. If the length is exactly 7, then it is assumed to be a "short numeric" phone number and the proper number is added to it. If the phone number is not any of these, then the formula returns the text "Undetermined." After using this formula, you'll still need to format the resulting cells using the special Phone Number format.

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