EIN for 1099

I have a non-grantor Trust. The non-grantor Trust is the sole member of a Holding Company. The Holding Company is the sole member of an Operating Company. Both the Holding Company and the Operating Company are disregarded entities. A 1099 will be issued for work that will be done by the Operating Company. What EIN do I give for the 1099 (EIN of the Trust, Holding Company, or Operating Company)?