Toilet trouble

Moved into new house and noticed toilet has no overflow pipe to outside of house, what happens if ballcock fails? Toilet looks fairly new and modern with no hole for a overflow.

If it is a modern new one it might have an internal overflow.

Take the lid off and see if there is an open pipe pointing up from the flushing mechanism just above water level. If you hold the float down so that more water flows into the cistern, you ought to see the excess water spilling down this pipe and running into the pan.

Thanks JohnD, I can`t see a pipe but i held down the ballcock and water overflowed into the pan.