This may apply to mortgages that close on any day other than the requested day of payment. For instances: since some lenders want monthly payments to be made on the first day of the month, they will adjust the interest due on closing so that interest on your mortgage is paid up until the first of the coming month. If you close on the 20th of the month (and the month has 30 days), you will have to pay interest for 10 days so that you are paid up until the first of the coming month. Then your first full mortgage payment will be due on the first of the following month.