Some 36 million American families have received letters from the Internal Revenue Service (IRS) notifying them they are eligible for monthly payments of up to $300 per child by expanding an existing tax credit. These payments, approved as part of the American Rescue Plan, allows families to receive a $3,000 annual benefit ($250 each month) for each child aged 6-17 and $3,600 (or $300 a month) for each child under age 6 for the 2021 tax year. What You May Not Know The payments received in…