Washington has three different types of orders to prevent communication between persons.
No Contact Orders are issued by a criminal court in conjunction with a criminal proceeding. You cannot go get one unless he's been charged with a crime all ready.
DVRO's are granted when you have a previous relationship as spouses. Arguably yes you could get a DV order on these facts, but as you say, you have ongoing financial ties with your ex and need to communicate about these matters. A DVRO at this point would interfere with that communication.
An Anti-Harassment Order would apply if you were not previously married to this person, for example, if they were your neighbor or some other relationship besides spouse/former romantic partner.
As you have advised him you no longer wish to receive non-business related communications, arguably you could get an order saying so.
And as always, if you get something threatening that advises you to beware for your health and safety, you can contact law enforcement directly.
I know this wasn't really what you asked, but I hope it helps you figure out what to do. Elizabeth Powell
Using Avvo does not form an attorney client relationship.
I simple solution might work, and cost a lot less time and money. Make an appointment with an experienced family law attorney, and have him/her send you former spouse a strongly worded letter spelling out exactly what will happen if there is a repeat of this behavior. I have found that this often works, and the cost is just that of a letter.
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