Hello, this is my second year preparing tax returns, I am fairly new at it. I just filed a client's tax return las month, and I accidently made an error on one of the questions in Schedule 8812, Line 13, question A1; it asked if the client had a place of abode (residence) in the US for more than half of 2021, I checked box "No", but it should have been checked "YES".

The IRS adjusted her tax return , and because of my mistake, the IRS is not recognizing her eligibility for child tax credit and the recovery rebate credit. 

Can I amend the return? I would really appreciate the advice. I have tried calling the IRS but I have no luck speaking with them. 

Thank you,