Can a mortgage company modify a loan without both borrowers consent?

Most times no. The loan is a contract that requires all parties to agree to change. Both borrowers are usually needed to sign off on a modification.

Unless a borrower or co-borrower is deceased or aborrower and a co-borrower are divorced, all parties who signed the originalloan documents or their duly authorized representative(s) must execute the HAMPdocuments. If a borrower and a co-borrower are divorced and the property hasbeen transferred to one spouse in the divorce decree, the spouse who no longerhas an interest in the property is not required to execute the HAMP documents.Servicers may evaluate requests on a case-by-case basis when the borrower isunable to sign due to circumstances such as mental incapacity, militarydeployment, etc. Furthermore, a borrower may elect to add a new co-borrower.

Generally, a contract cannot be modified without the consent of all parties (borrower, lender, trustee on a deed of trust, etc.). The lender could accept less money, but the borrower could not rely on the new arrangements without a written modification. If the lender has modified the loan to your detriment, you could sue for damages. If the loan was modified to your benefit, you might be able to enforce it but you would need to evaluate the consideration or details of the bargain.

No. All borrowers have to consent to a change in the terms unless the bank unilaterally lets one person off the note, which never happens.