The IRS opens up for processing on Monday, January 27, except for a few returns they pulled early for testing purposes.   

Although the IRS can start processing such returns with EIC or ACTC, by law the IRS will not begin issuing refunds on tax returns claiming the Earned Income Tax Credit or Additional Child Tax Credit until February 15 at the earliest. 

WMR on IRS.gov and the IRS2Go app will be updated with projected deposit dates for most early EITC/ACTC refund filers by February 22. So EITC /ACTC filers will not see an update to their refund status for several days after Feb. 15.

https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions