Common causes
Worn sway bar links, bushes, ball joints, shock absorber mounts or tie rod ends. On some cars a loose exhaust or heat shield also knocks.
When turning
A clicking when turning at full lock can be a worn CV joint on front-wheel-drive cars.
WOF
Excess play in ball joints and steering parts is a WOF fail, so catching it early helps.
What to tell the mechanic
Which corner it seems to come from, whether it is over bumps, turning or braking, and recent tyre or suspension work.
Safe to drive?
Usually fine to drive carefully to a booking. A sudden change in steering feel, wandering or a loud bang: stop and get it checked.
General guidance only, not a diagnosis. If in doubt, do not drive it and have it inspected. In an emergency, call 111.
Who can help
Get quotes for car repairs near you
Questions
Can a mobile mechanic check it?
Many can do a visual check, but some play is only found on a hoist.
What should I put in the job?
Where and when you hear it.