Homeowners seeking relief under the Obama administration's mortgage aid program must provide proof of their incomes upfront, the Treasury Department says.

Borrowers had been able to state their income verbally and provide documentation later. That caused the program to struggle after many borrowers did not return the documents.

Lenders will now be required to collect two recent pay stubs at the start of the process. Borrowers will have to give the Internal Revenue Service permission to provide their most recent tax returns, rather than submitting the returns themselves.

The changes become mandatory for modifications made starting June 1.