Wash. Rev. Code § 68.40.010
A cemetery authority not exempt under this chapter shall deposit in an endowment care fund not less than the following amounts for plots or interment rights sold: Ten percent of the gross sales price for each grave, niche, or crypt.
In the event that a cemetery authority sells an interment right at a price that is less than its current list price, or gives away, bequeaths, or otherwise gives title to an interment right, the interment right shall be endowed at the rate at which it would normally be endowed.
The deposits shall be made not later than the twentieth day of the month following the final payment on the sale price. If a contract for interment rights is sold, pledged, or otherwise encumbered as security for a loan by the cemetery authority, the cemetery authority shall pay into the endowment care fund ten percent of the gross sales price of the interment right within twenty days of receipt of payment of the proceeds from such sale or loan.
Any cemetery hereafter established shall have deposited in an endowment care fund the sum of twenty-five thousand dollars before selling any interment right.
RCW 68.40.010