BobKamman
Level 15

@lucrecia " Or would the IRS do an another recalculation based on UCE? "

Yes, eventually.  They won't recalculate RRC because it appears the taxpayers already received the full amount to which they are entitled.  But they will recalculate tax, and perhaps other credits, based on UCE.  That's not going to happen until July at the earliest, so it depends on whether your clients want to ignore a few notices with increasingly threatening language churned out by the ol' IRS computer.  You might be able to freeze the notices by filing an amended return, which is permitted but not encouraged, or even making a phone call to ACS and explaining the situation.