Field 901 Interest in the Mortgage Banker Master Record is to compute the odd days interest from the closing date to the date amortization interest commences.

Almost all the time, these days are from the closing date to the date one month before the first payment date as shown in Field 315 First Payment Date. Example:

The loan closes on July 15th (Field 314 Est/Close Date) with the first payment due September 1st (Field 315 First Payment Date). The Field 901 Odd Days Interest would be from the 15th to the 1st day of August. (07-15-YY to 08-01-YY)

Over the years we learned that some borrowers do not have sufficient cash to pay closing costs and the up-front Odd Days Interest. So, MC added the feature of negative Odd Days Interest capability.

As a personal policy (why software was programmed), if the loan closed between the 2nd and the 15th day of the month and the borrower did not have sufficient cash at closing, but could have money to pay the monthly payment earlier, we offered the Negative Odd Days.

Example of above loan with Negative Odd Days Interest:

Field 314 Est/Closing Date is July 15, YYYY.
Field 315 First Payment Date would be August 1, YYYY.

Field 901 Interest would be 07-01-YY. Interest would be from 07-15-YY back to 07-01-YY. The borrower would receive a credit for 14 days of interest. When the August 1st payment is made, the lender will receive interest for the entire month (07-01-YY to 08-01-YY) and would recover the negative advanced interest. This does not affect interest accruals.