I have a related question to this:  If a taxpayer has set their W-4 to withhold taxes perfectly based on the old $2k per child credit (i.e. they would owe near zero on their tax return), and now the IRS is going to pay them $1,500 for a child between 6 & 17, the taxpayer could end up owing $500 on their tax return per child  (the reduced withholding of $2k + $1,500 cash rec'd = $3,500 advanced - $3,000 credit = $500 owed). 

For some low-income individuals, this could be an unexpected burden.  Has anyone heard how the IRS is addressing this possibility?  If the child is under 6, the burden would be $200 per child. 

This could be a reason that someone could opt-out of the advance payments, but low income individuals do not usually have a tax preparer to give them this kind of advice.  Said a different way, turning down money is hard!  Curious other's thoughts.