Illegal immigrants have been collecting the payoff from the “refundable” tax credit for years because of an IRS interpretation of how the rule was drafted. The Republican-controlled Congress this fall had a chance to correct that in the tax code overhaul that in the Senate version doubled the child tax credit to $2,000 and expanded eligibility.

The House bill increased the child tax credit to $1,600 and upped the income cutoff to receive it.

Both bills neglect to require that the worker have a Social Security number to claim the credit but require only that the qualifying child have a Social Security number.