When you make a late mortgage payment the bank will usually charge you a late fee which will be applied to the balance of the mortgage making it harder to pay off the mortgage.
If you make late mortgage payments you need to factor in the late fee and pay the late fee along with the late mortgage payment to avoid any foreclosure.
If the late fees accumulate too much then yes the bank will likely foreclose on you so make sure you cover those late fees as well.
However the late fees will usually have to build up over a year or two before the bank decides to foreclose on your home.