---
search:
  tags:
    - billing
    - POST
seo:
  description: >-
    Marks the second reminder for an invoice… Reference for the POST
    /billing/invoices/{id}/mark-second-reminder-as-sent endpoint in the Leadtime
    Public API API.
sidebar:
  badge: POST
  label: Mark second reminder as sent
title: Mark second reminder as sent
type: openapi-operation
---
Marks the second reminder for an invoice as sent to the customer. This records the second reminder date and contact information.

**What happens when you mark a second reminder as sent:**
1. Second reminder date (`secondReminderAt`) is recorded as the current date
2. Second reminder type is set to "Manual" (indicating manual marking, not email sending)
3. Contact recipient is recorded (from invoice contactId)
4. User who marked it as sent is recorded

**Important restrictions:**
- Only invoices with status "New" or "Sent" can have reminders marked as sent
- The invoice must be overdue (past its due date) to send reminders
- A first reminder should typically be sent before a second reminder
- This endpoint marks the reminder as sent manually (use send reminder endpoint for email sending)

**Use cases:**
- Record that a second reminder was sent manually (e.g., via postal mail or other channels)
- Update reminder status after external sending
- Track reminder history

**What is returned:**
- Success response confirming the second reminder was marked as sent

<Operation source="api-reference" id="invoicescontroller-marksecondreminderassent" />