Wyo. Stat. § 40-14-246: Notice of assignment.

The buyer or lessee is authorized to pay the original seller or lessor until the buyer or lessee receives notification of assignment of the rights to payment pursuant to a consumer credit sale or consumer lease and that payment is to be made to the assignee. A notification which does not reasonably identify the rights assigned is ineffective. If requested by the buyer or lessee, the assignee must seasonably furnish reasonable proof that the assignment has been made and unless he does so the buyer or lessee may pay the seller or lessor.