Child Benefit is affected by the benefit cap. This sets the maximum yearly total you can get on benefits. What you get depends on where you live and your circumstances (for example, a single parent living with children is limited to £22,020 a year outside London but for the same situation it's capped at £25,323 in the capital). So if you're close to your limit and claim Child Benefit, your award may be capped, but there are exceptions.