Parents with children (at least until the age of 18) are entitled to receive German child benefit payments. This benefit amounts to 194 EUR per month for the 1st and 2nd child, 200 EUR per month for the 3rd child and 225 EUR per month for each additional child. These amounts are valid for 2018 and are regularly increased by the government.
Especially when arriving in Germany or living and working in Germany for a certain period, parents should definitely apply for this child benefit. At least within each tax return a calculation between the tax benefit based on deduction for each child (Kinderfreibetrag) versus the child benefit you are entitled to (Kindergeld) will be made. When filing a tax declaration, it is not important whether you received such benefit but whether you are entitled to it. Just for that reason such an application should be filed in any case – either to realise this payment or to get a negative assessment which is useful for tax reasons.
PLEASE NOTE: As of 1 January 2018 child benefits will be assessed retroactively for 6 months only starting with the date the application has been filed with the authority. (In the past this period was 4 years.) For that reason such application should be filed really soon after arrival in Germany.