(a) If your actual washing allowance is less than the amount that you claimed on form ONRR-4430 for each month during the allowance reporting period, you must pay additional royalties due, plus late payment interest calculated under § 1218.202 of this chapter from the date when you took the deduction to the date when you repay the difference.

(b) If the actual washing allowance is greater than the amount that you claimed on form ONRR-4430 for any month during the period reported on the allowance form, you are entitled to a credit without interest.