SMS Payment Reminders

Text a client their total overdue balance, after previewing the exact message.

2 min read
Updated Sep 18, 2026
Invoices

SMS Payment Reminders

When a client is behind on payment you can send them one text message that quotes everything they owe you on overdue invoices, and points them to their emails and the customer portal.

Sending One

The Send SMS reminder action is in three places:

  • the client's page, in the ⋯ menu next to Edit;
  • an invoice's page, in the actions menu next to Send reminder;
  • the invoice list, in each row's menu.

All three open the same preview. It shows the number the text goes to, the message exactly as the client will receive it, how many characters and SMS parts it uses, and the overdue invoices behind the total. Nothing is sent until you press Send SMS; Cancel closes it without sending.

The message reads:

Hello <client>, your invoices with <your company> are now overdue. Total balance is £<amount>. Please check your email for invoices or your customer portal at portal.dynamik.app

What Counts as Overdue

The total adds up the amount due on every invoice of that client that is unpaid or partly paid and whose due date has passed. Credit notes, paid invoices and invoices not yet due are left out, so opening it from one invoice still quotes the client's whole overdue balance.

Which Number Is Used

The client's Mobile, or their Phone when there is no mobile. A number starting with 0 is treated as a UK number. The action only appears when the client has one of the two.

Afterwards

Each invoice included in the total gets an entry in its activity: Overdue SMS reminder sent to <number>.

Note

SMS reminders are sent only when you press the button — the automatic reminders on a schedule are emails. If the preview says the client has no overdue invoices or no number, fix the client record or the invoice due date first.