It would violate RESPA: You cannot pay referral fees on a consumer mortgage loan.
1024.14—Prohibition against kickbacks and unearned fees.
(a) Section 8 violation. Any violation of this section is a violation of section 8 of RESPA (12 U.S.C. 2607).
(b) No referral fees. No person shall give and no person shall accept any fee, kickback or other thing of value pursuant to any agreement or understanding, oral or otherwise, that business incident to or part of a settlement service involving a federally related mortgage loan shall be referred to any person. Any referral of a settlement service is not a compensable service, except as set forth in §1024.14(g)(1). A company may not pay any other company or the employees of any other company for the referral of settlement service business.