One party with multiple accounts get the same dunnings

Hello,

We are now using the bill-to level to send dunnings to our customers. Some parties has multiple accounts and when we want to sent the dunning, each account of one party gets the same dunning letter. So one party with three accounts, generates three dunnings with the same information. How can we avoid that one bill-to gets three the same dunnings?

I hope someone can explain this to me.

Regards,

Patricia