Instead of adding blank rows, you could use conditional formatting to
shade the rows where the CIF changes. For example:

Select your data, starting in row 2 (cells A2:G1000 in this example)
Choose FormatConditional Formatting
From the first dropdown, choose Formula Is
In the formula box, enter a formula that refers to the cell that
contains the CIF (C2):
=$C2<$C1
Click the Format button, and on the Patterns tab, select a colour
Click OK, click OK

This will make it easier to spot the customers in the list, and won't
interfere with other features, such as filtering, sorting and creating
pivot tables.


David Noel wrote:
I have a spreadsheet with a unique identifier for each
customer, Customer Information File (CIF). Whenever this
number changes, I want to automatically insert a blank
row. This will merely making the the spreadsheet more
pleasing to the eye to read. Keep in mind, there may not
be a break in CIF for 1 to 15 lines, but whenever this
CIF number changes, I want a new blank row.

Any help would be greatly appreciated!!

David


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html