Michael,

I'm not sure if you want to compare the data in the existing worksheets, or
in a new worksheet, but I'll give you what I have put together.

In the last column of the May sheet, place the following formula:
=IF(ISNA(VLOOKUP(A2,June!$A$1:$D$10,1,FALSE)),"Closed","Carried Forward")
A2 is your your loan number in the May worksheet.  June!$A$1:$D$10 is the
data table in the June worksheet.  If no loan number is found, the cell is
marked "Closed", otherwise the loan was carried forward to June.

Likewise, in the last column of your June table, place the following
formula:  =IF(ISNA(VLOOKUP(A2,May!$A$1:$D$10,1,FALSE)),"New
Account","Existing")
A2 is your loan number in the June worksheet.  May!$A$1:$D$10,1 is the data
table in the May worksheet.  If no loan number is found, the cell is marked
as a "New Loan" for June, otherwise the loan is found in the May worksheet
and marked as "Existing".

Change the table references as needed and copy the forumla down to the last
row of your data table.

Regards,
Michael