All monetary contributions from political committees, political parties and caucus political committees must be by written instrument (e.g., check, money order, cashiers check).  Those from individuals, associations, unions or businesses must be by written instrument if the contribution is more than $100.

Cash contributions must be deposited into the campaign bank account, and not spent directly or mingled with petty cash.  Monetary contributions are required to be deposited into the campaign account within five business days of receipt..  RCW 42.17A.475.