In the past, taxpayers could claim a child tax credit on an amended or late-filed return with an SSN or ITIN obtained after the return's original due date, this will not be the case going forward.

Sections 205 and 206 of the PATH Act added limitations on claiming the child tax credit, including the additional child tax credit by providing that a taxpayer identification number can be used to claim those credits only if it was issued on or before the due date of the return. These provisions disallow retroactive filing of either amended or original prior-year returns that were due before issuance of the ITIN to claim the child tax credit.