Event, the other company owed us money, and we decided to stop supplying if the other party didn't pay it back. What notice should I give? How to write it is euphemistic.
Just say it. Tell the truth and remind him of the company, in the name of your company. Sign with an official avatar. If you are afraid of affecting the relationship, then write a dunning letter in the name of the person in charge (manager) and formally sign it. But because it was personal, it didn't hurt face or offend each other.