Example. B is a sublessor of a coal lease; A is the lessor; and C is the sublessee. B pays A a royalty of 50 cents per ton. C pays B a royalty of 60 cents per ton. The amount realized by B under section 631(c) is 60 cents per ton and will be reduced by the adjusted depletion basis of 50 cents per ton, leaving a gain of 10 cents per ton taxable under section 631(c).
Example. Assume the same facts as in example 1, except that E agrees to pay a sum of money to C in return for 10 cents per ton on the coal mined by C. E has an economic interest, since he must look solely to the extraction of the coal for the return of his investment. However, E has not made a disposal of coal under a contract wherein he retains an economic interest, and, therefore does not qualify under section 631(c). E is entitled to depletion on his royalties.
Example. A acquires coal rights on January 1. On January 30, A enters into a contract of disposal providing that mining shall begin July 2, and mining actually begins no earlier. Any advance payments which A receives qualify under section 631(c).
26 C.F.R. §1.631-3