1A written reminder or dunning letter sent to request payment, submission of documents, etc.; often synonymous with '督促状'.
家賃の滞納で管理会社から催促状が届いた。
A reminder letter arrived from the management company because of overdue rent.
催促状を受け取ったら、まず支払方法について問い合わせるとよい。
If you receive a dunning letter, it's best to first inquire about payment options.