Credit Line Tracking
 

I have a workbook that has 2 spreadsheets in it or tab #1 and tab #2 if you
will.
Someone helped me eons ago put this together, but they are no longer around.
I am tracking Credit lines for my family in tab #2 for each month, I simply
enter in the balance owed, interest charged, and payment due.

What I have on tab #1 is a Balance summary screen or a snapshot of the very
latest outstanding balance by month for a particular creditor based off of
what was entered into tab #2. (Update tab #2, tab #1 should automatically
update.)
I have 2 issues. The first one is that I cannot add in new credit lines as
they appear, I cannot click and drag anything or if it is a matter of
updating formulas I cannot do that.

The other issue is when a new creditor comes, the formulas I do have,
do not read the cells correctly. For example, say I have an Capital One card
that has balances from January thru May, is paid down to Zero in May and shows
June, July, and August Zero. If I turn around and spend say $100 in September
$100 should show under the balance column in tab # 2, then tab #1 should read
that as well. Instead it reads as Zero or N/A , in tab #1 balance column for
Capital One. Any Ideas on what I can do to improve this?

Thanks in advance.