You might be thinking of the maximum of three children for whom you can receive earned income credit. Even if you have more than three children you cannot get EIC for more than three. But as TurboTax Ashby said, you can claim as many children as you actually have as your dependents. The child-related credits you can get will be affected by their ages and by your earned income.
Look at your 2018 tax return to see the child-related /dependent credits you received:
Child tax credit line 12a
Additional Child Tax Credit line 17b (schedule 8812)
Credit for Other Dependents line 12a
Earned Income Credit (EIC) line 17a
Child and Dependent Care Credit line 12 (comes from Schedule 3 Form 2441)
The dependents you listed are on the first page of your Form 1040 below your address.
https://ttlc.intuit.com/questions/1900923-what-is-the-child-tax-credit
https://ttlc.intuit.com/questions/1900643-what-is-the-child-and-dependent-care-credit
https://ttlc.intuit.com/questions/1899157-what-are-the-qualifications-for-the-earned-income-credit-e...
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/use-the-eitc-assistant
https://ttlc.intuit.com/questions/4499708-what-is-the-500-credit-for-other-dependents-family-tax-cre...
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
