Why does my toilet keep blocking?

A toilet that blocks again and again is telling you something. The usual causes, what you can safely do, and how a camera finds the real fault.

A plumber answers 24/7.

Key takeaways

One blockage can be bad luck. Two or three in a few months almost always means something in the pan or the pipe is catching waste.
Sydney Water's rule is to flush only pee, poo and toilet paper. Non-flushable wipes, paper towel and sanitary products go in the bin.
If the shower or floor waste backs up when you flush, or the yard gully overflows, the blockage is in the drain past the toilet, not the toilet itself.
After a repeat blockage, a CCTV camera inspection shows whether roots, a sag or a broken joint is the cause, so the repair targets the cause.