Homebuyers can be interested in assuming a mortgage when the rate on the existing loan is significantly lower than current rates. For example, if the seller has a 2.25% interest rate on their mortgage and current rates are 3.25%, it might make sense for you to assume the seller’s mortgage. Homebuyers can also be interested in assuming a mortgage when the seller does not have much equity in their home. That’s because these purchases do not require a large down payment.