But if you send the bank 1/2 of your payment they will apply it ALL to interest so you’re not reducing principal thus making no difference.
Interest is calculated on a full month basis. As soon as the bank applies a payment, they will send you another statement for the next month. You can make your mortgage payments early but you will not reduce principal by making more frequent or early payments (even if, in January you make 1 year’s worth of mortgage and interest payments in advance of when they are due).
The only way to reduce principal is to make additional principal payments on top of your normal monthly payments (more cash flow out of your pocket).
PS: There are some services that purport to do it for you for a fee. They don’t work and what you pay in fee is more costly.
