Which of the following actions would NOT typically relieve a seller from liability on a previously assumed mortgage?

The action that would not typically relieve a seller from liability on a previously assumed mortgage is increasing the mortgage amount. When a seller assumes a mortgage, they are held liable for the debt even if the majority of obligations are transferred to the buyer. Increasing the mortgage amount does not change the fundamental responsibility of the seller for the existing mortgage, as this action usually involves adding more debt rather than discharging or eliminating the seller’s liability.

In contrast, refinancing the mortgage, signing a substitution agreement, or creating a new loan agreement could potentially relieve the seller of the original mortgage liability. These actions often involve restructuring or replacing the existing loan terms, ideally resulting in a release from the seller’s obligations under the assumed mortgage. However, simply increasing the mortgage amount does not provide such relief, because the seller's original accountability remains intact.