Wow, thank you for your detailed explanation!

I understand it much better now. However, the issue with using the listindex is that although the combobox items populate according to the fields that are filled in "Contact Details", if the form is not entirely filled out, the corresponding values that will be reflected in "Summary" would still be in order.
(e.g. if I fill out details for Client 1, FA 1, and Cuscontact 1 only, the combobox will populate "Client 1", "FA 1", Cuscontact 1". However, when the item "FA 1" is selected, "Summary" sheet will populate the values that are supposed to be for "Client 2" (Row 5 in "Contact Details"), causing the "Summary" sheet to return blank values.)

It would be great if you could advise me on how I could overcome this.
Regardless, I really appreciate you taking the time to explain your code to me! You taught me to think analytically when creating codes and exposed me to uses of different methods such as an array.