There is a master id table, but there is always at least one record for each id in each table. When an initial record is added to table1 by subid owed field, one is added to table2. There could be numerous records in table2 to equal the value in the single record paid field in table1 for each subid.

For instance:

link id = 1

Table1:

Id             owed      paid  subid
1    rcd1    175.00    125.00     22
1    rcd2     50.00      0.00     23

Table2:

Id            tpaid            subid
1    rcd1   -175.00               22  && matches rcd1 field owed in table1
1    rcd2     50.00               22  && rcd2+rc3+rcd4 of table2 = table1 rcd1 field paid
1    rcd3     50.00               22
1    rcd4     25.00               22
1    rcd5    -50.00               23  && matches rcd2 field owed in table1

If I match up tpaid in table2 to paid in table1 for > 0 it should equal
If I match up tpaid in table2 to owed in table2 for < 0 in table2 and > 0 in table1 it should equal
summing tpaid for id = 1 in table2 should equal the sum of owed-paid in table1