Child Tax Credit
You can claim Child Tax Credit whether you're in work or not.
There's no limit on what you can earn in your job if you're claiming Child Tax Credit. If you have a high income you're less likely to get Child Tax Credit.
How much you can claim
This depends on things like whether you pay for childcare and the number of children you have. You can be paid more if your child has a disability.
Use the GOV.UK tax credit calculator to see how much you can claim.