Send polite overdue invoice and fee reminders with a dry-run mode

Chasing late payments is awkward and easy to get wrong. This workflow reads a receivables Google Sheet every morning and picks the invoices that are overdue, not paid, not on hold, outside the cooldown since the last reminder and under the maximum number of reminders. It suits schools collecting tuition and other fees as well as small businesses chasing invoices. A language column lets parents or customers receive English, Arabic or both.

An AI model drafts a short, friendly reminder for each item using only the facts in the sheet. Code then checks every draft: the amount, invoice id and currency must appear, no number may appear that is not in the data, and threatening, legal or fee wording is blocked unless you have configured a late-fee policy. Drafts that fail are held back. Accounts that are very late or have already had the maximum number of reminders are not messaged at all; they are listed so a person can call.

The flow starts in dry-run mode. In a dry run it does everything except send and log, and returns the full list of messages it would have sent, so you can judge the tone and the selection for a few days. When you switch dry run off, a person must approve the whole batch in the Cadrix approval inbox before a single message goes out. Approved reminders are sent by WhatsApp or Outlook email and written to a reminder-log tab, which is what enforces the cooldown. The flow never edits your receivables tab. Check local rules on debt reminders and WhatsApp business messaging before going live; first-contact WhatsApp messages usually need an approved template.