An assumption is a clause in the contract that allows the seller to pass the mortgage's responsibility to the buyer. This way, they immediately become the property's new owner and must pay for the mortgage.
However, they need to be eligible by meeting specific qualifications, such as having a high enough credit score.
These deals become more attractive if the interest rates have recently increased or the buyer wishes to avoid closing costs. Nonetheless, this must be approved by the bank, which sometimes may be reluctant as lenders don't know about the ability of the new owner to pay the loan.