there is nothing the IRS will do. claim the dependent on your return. you will have to paper file if they file first. eventually, the IRS will contact both parties. 1st asking to amend and if neither party does a second notice that asks each to provide proof they are entitled to claim. the loser gets a bill. if you think the dependent's identity was stolen then file form 14039
https://www.irs.gov/pub/irs-pdf/f14039.pdf
you will have to either fax or mail the form. if you mail the form use a method where you get proof of delivery. it can be sent now. if mailed it might take the IRS 4 months or longer to process - way behind in processing mailed in forms and returns. people have also reported problems with faxing.
