Could someone please help me with this translation.
As mentioned, context is essential, but in the context of credit, you might say "verificación de referencias crediticias." If the context is personal references for a job, you might say "verificación de referencias personales."
As Heidita has mentioned we need a litle more information. If by reference check, you are relating to "verifying someone´s credit worthiness" this could be translated as "informe de crédito". If you are referring to checking a testimonial this could be "referencia or informe" example, Ella tiene buenas/buenos referencias/informes, She has good references, however, to get a fuller picture, why not put it in a sentence.
WE need some context here.