RCW 11.76.100: Receipts for expenses from personal representative.

In rendering his or her accounts or reports the personal representative shall produce receipts or canceled checks for the expenses and charges which he or she shall have paid, which receipts shall be filed and remain in court until the probate has been completed and the personal representative has been discharged; however, he or she may be allowed any item of expenditure, not exceeding twenty dollars, for which no receipt is produced, if such item be supported by his or her own oath, but such allowances without receipts shall not exceed the sum of three hundred dollars in any one estate.