Dear Market Participants:

An error has been discovered in the instructions issued on 5/7/01 to reconcile
customer invoices.  You will need to use V-4 NOT V-5 when calculating the net
payment for December 8th.

Regards,

Market Relations
518-356-6060
---------------------- Forwarded by Market Relations/NYISO on 05/09/2001 04:28
PM ---------------------------


rbowers@nyiso.com on 05/07/2001 04:10:19 PM

Please respond to market_relations@nyiso.com

To:
cc:   recipient list not shown: ; (bcc: Market Relations/NYISO)

Subject:  April 2001, December 2000 4-month, & October 6-month Invoice
      Banking Instructions



The NYISO will be posting invoices for the April 2001 initial invoice,
October, 2000 6-month settlement adjustment, and December, 2000 4-month
settlement adjustment by 2300 May 7, 2001.


Funds due the NYISO for April 2001 settlements are to be transferred into
the NYISO Clearing Account by close of business Wednesday, May 16, 2001. Funds
due the NYISO for the December 2000 4-month settlement adjustment are to be
transferred into the NYISO Clearing Account by close of business Thursday,
May 17, 2001. Funds due the NYISO for the October 2000 6-month settlement
adjustment are to be transferred into the NYISO Clearing Account by close of
business Friday, May 18, 2001.


Funds due Market Participants from the NYISO for April 2001 settlements will 
be
transferred into Market Participant accounts by close of business Monday,
May 21, 2001. Funds due Market Participants from the NYISO for the December
4-month settlement adjustment will be transferred into Market Participant
accounts
by close of business Tuesday, May 22, 2001. Funds due Market Participants from
the
NYISO for the October 6-month settlement adjustment will be transferred into
Market
Participant accounts by close of business Wednesday, May 23, 2001.


Please be aware that as per the ISO Services Tariff any disputed amounts are 
to
be paid in full.  Upon resolution of the dispute, if it is determined that an
overpayment has been made by the Customer, a refund, with interest, will be 
made
by the ISO

Attached please find banking instructions for the transfer of funds resulting
for these settlements.

In order to reconcile customer invoices for the December 2000 3-month 
settlement
adjustment, it will be necessary to net the following versions of the daily
advisory statements:

Date Current             Previous
1    V-4       minus          V-3
2    V-4       minus          V-3
3    V-4       minus          V-3
4    V-4       minus          V-3
5    V-4       minus          V-3
6    V-4       minus          V-3
7    V-4       minus          V-3
8    V-5       minus          V-3
9    V-4       minus          V-3
10   V-4       minus          V-3
11   V-4       minus          V-3
12   V-4       minus          V-3
13   V-4       minus          V-3
14   V-4       minus          V-3
15   V-4       minus          V-3
16   V-4       minus          V-3
17   V-3       minus          V-2
18   V-3       minus          V-2
19   V-3       minus          V-2
20   V-3       minus          V-2
21   V-3       minus          V-2
22   V-3       minus          V-2
23   V-3       minus          V-2
24   V-3       minus          V-2
25   V-3       minus          V-2
26   V-3       minus          V-2
27   V-3       minus          V-2
28   V-3       minus          V-2
29   V-3       minus          V-2
30   V-4       minus          V-3
31   V-3       minus          V-2


In order to reconcile customer invoices for the October 2000 6-month 
settlement
adjustment, it will be necessary to net the following versions of the daily
advisory statements:

Date Current             Previous
1    V-7       minus          V-5
2    V-7       minus          V-5
3    V-7       minus          V-5
4    V-7       minus          V-5
5    V-8       minus          V-6
6    V-8       minus          V-6
7    V-8       minus          V-6
8    V-7       minus          V-5
9    V-7       minus          V-5
10   V-7       minus          V-5
11   V-6       minus          V-4
12   V-6       minus          V-4
13   V-7       minus          V-5
14   V-7       minus          V-5
15   V-7       minus          V-5
16   V-7       minus          V-5
17   V-6       minus          V-4
18   V-6       minus          V-4
19   V-6       minus          V-4
20   V-7       minus          V-5
21   V-6       minus          V-4
22   V-6       minus          V-4
23   V-6       minus          V-4
24   V-6       minus          V-4
25   V-6       minus          V-4
26   V-6       minus          V-4
27   V-6       minus          V-4
28   V-6       minus          V-4
29   V-7       minus          V-5
30   V-6       minus          V-4
31   V-6       minus          V-4


In addition to adjustments to billing units due to the receipt of billing
quality
metering data, this settlement adjustment includes the following billing code
modifications/corrections:

   Billing code was modified to model scheduling & dispatch of grouped
   generators
   for settlement of energy & bid production cost guarantee payments.
   Generators
   affected by this modification should see proper payment of those 
quantities.
   Any
   costs incurred by the NYISO will be recovered from transmission customers
   through
   their OATT Schedule 1 residual & BPCG adjustments
   For the December settlement adjustment, billing code was modified to ensure
   that
   appropriate prices corrections resulting from ECA-B were captured in the
   billing.
   This may impact transmission customers whose transactions were subject to
   ECA-B
   treatment, resulting in transmission usage charge adjustments.  Any costs
   incurred
   by the NYISO will be recovered from transmission customers through their 
OATT
   Schedule 1 residual adjustment.
   For the December settlement adjustment, a number of grandfathered rights &
   TCC
   configurations were corrected.  Customers affected by this would see either
   their
   TCC's converted back to grandfathered rights, or vice versa.  Any excess or
   deficiency
   in cost recovery will be balanced with the Transmission Owners, based upon
   their
   respective megawatt-mile coefficients.
   There was a code modification to allow for Class 2 PURPA generators to sell
   all
   over-generation to the real-time market.  This would result in payment to
   those
   affected suppliers.    Any costs incurred by the NYISO will be recovered 
from
   transmission customers through their OATT Schedule 1 residual adjustment.

(See attached file: April_Banking_Instructions.PDF)


 - April_Banking_Instructions.PDF