A zipper lock has a combination locking system defined by dials and clutches and a key overriding mechanism. The lock has a pole to receive zipper pullers and a movable cover plate to block the pole when the lock is in the locked mode. The lock has a control plate with release slots. The control plate can be shifted only if the dials are set to the correct combination or when a correct key is used to turn a tumbler cylinder. The cover plate is engaged with a latch having a latch finger. When the lock is in the locked mode, the latch finger is blocked by the control plate, restricting movement of the latch. When the lock is in the unlocked mode, the latch finger can be moved into a release slot, allowing the latch and cover plate to move in order to clear the pole.