You will get a discharge document from the bank. You then go to the registry office and register the discharge to remove the lien in your property. You should always check your mortgage balance with the bank periodically or ask a mortgage agent (like me) to do it for you.

The best way is to call the bank and get an estimate. Banks have different methods of calculating penalty and even the banks cannot give a concrete number until the mortgage is discharge in favor with another lender. I normally blend this to the new mortgage to minimize cash out.