Break fee
A charge your bank may make if you leave a fixed rate early or pay more than it allows. The fee covers the interest the bank loses, so it's usually higher if rates have dropped since you fixed.
Each bank has its own name for it. ANZ calls it an early repayment recovery, ASB an early repayment adjustment, BNZ an early repayment charge, Kiwibank a fixed rate break cost and Westpac a prepayment cost. Ask your bank for a quote before you break a fixed rate or pay off a large lump sum. The mortgage calculator shows what extra repayments within your bank's limit would save.