Sprint’s prepaid brand Boost Mobile is seeking to poach customers from rivals T-Mobile, AT&T and Verizon with a new offer of up to 50 percent off their current monthly payment.

Now through April 5, Boost is offering a new set of family plans for those who make the switch with 10 GB of high-speed data per line. Under the deal, two lines start at $60 per month. The plans come with unlimited talk, text and 2G data, Boost said.

The deal extends to a maximum of four lines, the carrier said.

In order to take advantage of the of the discount, customers need to have a valid port-in number and must complete the transaction at a participating dealer. The discount is not available through Boost’s website.

Alongside the plan discount, Boost said it is offering a free phone or $50 instant device discount for every line a customer ports from T-Mobile, AT&T or Verizon. The selection of free phones includes the Alcatel OneTouch Elevate, Motorola Moto E, LG Tribute, LG Tribute 2 and ZTE Speed, the carrier said.