Child Tax Credit has been replaced by Universal Credit for most people. You can only make a new claim for Child Tax Credit if you:
get the severe disability premium (external link), or are entitled to it
got or were entitled to the severe disability premium in the last month, and you’re still eligible for it
If your child is 16, you can claim up until 31 August after their 16th birthday. If they are in approved education or training (external link), you can claim until their 20th birthday.
If you cannot make a new claim for Child Tax Credit, you may be able to apply for Universal Credit (external link) (or Pension Credit if you and your partner are State Pension age (external link) or over).
What you will get
The amount you can get depends on how many children you have got and whether you are:
Child Tax Credit will not affect your Child Benefit.
You can only claim Child Tax Credit for children you are responsible for (external link).