Washington Revised Code Title 83. Estate Taxation § 83.100.070. Interest on amount due--Penalty for late filing--Exceptions--Rules

(3)(a) If the Washington return is not filed when due under RCW 83.100.050 and the person required to file the Washington return under RCW 83.100.050 voluntarily files the Washington return with the department before the department notifies the person in writing that the department has determined that the person has not filed a Washington return, no penalty is imposed on the person required to file the Washington return.

(b) If the Washington return is not filed when due under RCW 83.100.050 and the person required to file the Washington return under RCW 83.100.050 does not file a return with the department before the department notifies the person in writing that the department has determined that the person has not filed a Washington return, the person required to file the Washington return shall pay, in addition to interest, a penalty equal to five percent of the tax due for each month after the date the return is due until filed. However, in no instance may the penalty exceed the lesser of twenty-five percent of the tax due or one thousand five hundred dollars.

(c) If the department finds that a return due under this chapter has not been filed by the due date, and the delinquency was the result of circumstances beyond the control of the responsible person, the department shall waive or cancel any penalties imposed under this chapter with respect to the filing of such a tax return. The department shall adopt rules for the waiver or cancellation of the penalties imposed by this section.