Jason Strickland, 35, of Alabama was also convicted of sexual assault for the July 2015 incident.
He received an automatic sentence of life because he has a 2006 felony conviction in connection with five rapes in Oklahoma.
A Dallas County jury convicted him in the latest case, and State District Judge Brandon Birmingham sentenced Strickland on Friday.
Strickland and the 15-year-old girl met online in 2015. He encouraged her to leave her Allen home and run away to him.
She planned to take a Greyhound bus to meet Strickland in Alabama, but first he planned for her to meet a second man.
Cuauhtemoc Munoz, 45, pleaded guilty to sex assault and trafficking a child in 2016 and received eight years in prison as part of a plea agreement in the case.
Munoz took the teen to a hotel, where he raped her while Strickland listened on the phone.