I had the following VBA that I use to format my reports:

Option Explicit

Sub boldFillRangeIfCBoldOrBNull()

Dim i As Integer

For i = 1 To 1000

If Cells(i, "c").Font.Bold = True Then
Range(Cells(i, "a"), Cells(i, "O")).Font.Bold = True
Range(Cells(i, "a"), Cells(i, "O")).Interior.ColorIndex = 15
End If

If Cells(i, "B") = "" Then
Range(Cells(i, "A"), Cells(i, "O")).Interior.ColorIndex = 19
End If

Next i

Reporting need have changed and the range of data varies by customer. My
spreadsheet could contain 5 rows or 5000 rows and the data may spread over
col c or it could extend to col JJ.

Can someone give me some idea as to how to get this to work on the existing
data?

Many Thanks in advance.

End Sub