Big Oil Bailout Prevention Trust Fund Act of 201 8 This bill amends the Internal Revenue Code to eliminate: (1) the $1 billion per incident limitation on expenditures from the Oil Spill Liability Trust Fund for cleanup of oil spills, (2) the $500 million per incident limitation on expenditures from the trust fund for natural resource damage assessments and claims in connection with oil spills, and (3) the limitation on the borrowing authority of the trust fund. The bill also amends the Oil Pollution Act of 1990 to direct the President to promulgate regulations to allow advance payments from the Oil Spill Liability Trust Fund to states and localities to prepare for and mitigate substantial threats from the discharge of oil.