UPB UPBUnpaid Principal Balance of a Mortgage Loan Mortgage LoanMortgage debt obligation evidenced, or when made will be evidenced, by the Loan Documents, or  a mortgage debt obligation with a Fannie Mae credit enhancement. Test Notes-SV Test Again Sub-bullet test1 Sub-bullet test2 when it is purchased by Fannie Mae Fannie MaeThis Glossary term Is Created Using Automation in Lower Environments and is used for testing purposes only!! .