Table of Contents

  1. Introduction

  2. Why Automating Customer Reminders Matters

  3. Overview of Reminder Features in Dolibarr

  4. Setting Up the Basics: Invoice and Payment Workflow

  5. Enabling and Configuring the Emailing Module

  6. Using the Built-In Reminder System for Overdue Invoices

  7. Automating Reminders with Scheduled Tasks (Cron)

  8. Customizing Email Templates for Different Reminder Scenarios

  9. Using the “Emailing” Module for Marketing and Soft Reminders

  10. Advanced Automation with Triggers and Workflows

  11. Integrating with External Reminder Tools (Mailchimp, SMTP, SMS)

  12. Best Practices for Reminder Schedules and Messaging

  13. Avoiding Common Mistakes in Automated Follow-ups

  14. Use Cases by Business Type (Freelancers, SMEs, Services, Retail)

  15. Metrics and Reporting: Measuring the Impact of Automation

  16. Final Thoughts and Strategic Recommendations

  17. Additional Resources

1. Introduction

Unpaid invoices are one of the most common challenges facing businesses of all sizes. Whether you're a freelancer, a startup, or a mid-sized company, chasing clients for payment manually is time-consuming and often uncomfortable.

Fortunately, Dolibarr ERP & CRM offers a suite of tools that allows you to automate client reminders for late payments, due invoices, or even follow-up communication. This article provides a comprehensive guide on how to implement and optimize these automation features using native tools and optional modules in Dolibarr.

Whether you’re just starting out or looking to professionalize your accounts receivable process, this article will walk you through step-by-step techniques, best practices, and real-world use cases.

2. Why Automating Customer Reminders Matters

Chasing invoices manually introduces several inefficiencies and risks:

  • Human error: forgetting to send reminders

  • Inconsistency: sending them late or not at all

  • Time cost: hours spent writing and following up

  • Poor cash flow: due to delayed payments

  • Strained relationships: when reminders are aggressive or misworded

With automation:

  • Reminders are sent consistently and on time

  • Messaging is standardized and professional

  • You save valuable admin time

  • Your DSO (Days Sales Outstanding) decreases

  • Your business appears more reliable and organized

Dolibarr lets you customize how and when reminders are sent, and allows you to track everything inside your ERP system.

3. Overview of Reminder Features in Dolibarr

Dolibarr includes several native features that support reminder automation:

  • Invoice tracking: Each invoice has a payment status and due date.

  • Email templates: Standardized messaging for different reminder types.

  • Automatic emails: Reminders based on invoice age or due date.

  • Scheduled tasks (cron jobs): Automation of actions like sending reminders.

  • The Emailing module: For campaigns and general communication.

  • Third-party integrations: SMTP, SMS, external CRM tools.

Additional modules (from Dolistore or custom-built) can extend this to include:

  • PDF attachments in reminders

  • Multi-level escalation logic

  • SMS reminders

  • Analytics and A/B testing of emails

4. Setting Up the Basics: Invoice and Payment Workflow

Before automating anything, your invoice creation and validation workflow must be properly configured.

Step 1: Create and Validate Invoices

Navigate to:
Billing > New Invoice

Ensure each invoice:

  • Is linked to a valid third party (client)

  • Has a clear due date (based on payment terms)

  • Is validated (status changes from draft to validated)

Step 2: Define Payment Terms

Configure under:
Setup > Dictionaries > Payment Terms

For example:

  • Net 15

  • Due on receipt

  • 30 days end of month

These terms define the due date used for reminders.

Step 3: Track Payments

Dolibarr tracks when a payment is made. You can:

  • Enter payments manually

  • Reconcile via bank import (Bank module)

  • Use payment plugins for automatic matching

Only unpaid invoices are targeted by the reminder system.

5. Enabling and Configuring the Emailing Module

To send automated emails, ensure the Email module is active.

Activation

Go to:
Home > Setup > Modules/Applications > Emailing

Enable the module and configure:

  • Outgoing email server (SMTP)

  • Default sender address

  • Email signature

  • BCC and logging preferences

SMTP Setup

For Gmail, Outlook, or custom SMTP:

  • Host: smtp.example.com

  • Port: 587 or 465

  • Authentication: Yes

  • TLS/SSL: Enabled

You can test email delivery from within the configuration page.

6. Using the Built-In Reminder System for Overdue Invoices

Dolibarr includes a reminder feature for overdue invoices, often referred to as "Automatic reminder emails."

How It Works

  • A background task checks for unpaid invoices past due

  • If a match is found, a reminder email is sent

  • Email content is based on a predefined template

Configuration Steps

  1. Go to Setup > Modules > Invoice > Options

  2. Enable Automatic reminder emails

  3. Choose delay (e.g., send after 5 days overdue)

  4. Link to a predefined email template

  5. Choose to send with or without PDF attachment

  6. Enable logging if desired

These reminders run via cron job, ensuring they are sent automatically every day.

7. Automating Reminders with Scheduled Tasks (Cron)

For reminders to send automatically, cron tasks must be configured.

What Is Cron?

Cron is a Unix/Linux-based task scheduler. Dolibarr uses it to trigger background tasks like:

  • Sending invoice reminders

  • Creating recurring invoices

  • Emailing reports

Setup in Dolibarr

Go to:
Home > Admin Tools > Scheduled Jobs

Ensure the invoice reminder job is active:

  • Task name: send_email_reminder

  • Frequency: daily (or as needed)

  • Status: enabled

You can configure these either:

  • Internally via Dolibarr’s scheduler (web cron)

  • Externally using server-side cron (recommended for production)

8. Customizing Email Templates for Different Reminder Scenarios

Dolibarr supports template-based email messaging for consistency.

Email Template Setup

Navigate to:
Setup > Emails > Email Templates

Create templates for:

  • First Reminder (polite tone, gentle nudge)

  • Second Reminder (firm tone, include payment options)

  • Final Notice (formal, mention penalties if applicable)

Each template can include dynamic variables like:

  • __CLIENT_NAME__

  • __INVOICE_REF__

  • __AMOUNT__

  • __DUE_DATE__

Example:

vbnet

Subject: Reminder - Invoice __INVOICE_REF__ is overdue Hello __CLIENT_NAME__, This is a friendly reminder that invoice __INVOICE_REF__ amounting to __AMOUNT__ was due on __DUE_DATE__. Please arrange for payment at your earliest convenience. Regards, __USER_SIGNATURE__

These templates are linked to automatic reminders via the invoice module settings.

 

9. Using the “Emailing” Module for Marketing and Soft Reminders

While the invoice reminder system handles financial follow-ups, Dolibarr's Emailing module can be used for softer, proactive communication like:

  • Gentle reminders before an invoice is due

  • Payment method instructions

  • Thank-you emails after payment

  • Promotional follow-ups with links to pay online

How to Use It

  1. Activate the Emailing module:
    Setup > Modules > Emailing

  2. Create a new campaign:
    Emailing > New Emailing

  3. Choose target:
    Select clients with unpaid invoices using filters in the emailing wizard.

  4. Compose message using a template or new draft.

  5. Schedule for later or send immediately.

Example Use Cases

  • 3 Days Before Due Date: “Just a heads-up that your invoice is due soon.”

  • After Payment: “Thanks for your recent payment. Here’s your receipt.”

  • Overdue But Friendly: “Still waiting on your payment for invoice #XXXX.”

This module is best used when you want more control over timing and tone.

10. Advanced Automation with Triggers and Workflows

If your business logic goes beyond standard reminders, you can use Dolibarr's triggers and custom workflows to automate complex actions.

Using Triggers

Dolibarr has an event system where specific actions (like invoice validation) can trigger code execution.

Example trigger:

  • BILL_VALIDATE – trigger runs when an invoice is validated

  • BILL_PAYED – trigger runs when invoice is marked as paid

You can add custom code in:
htdocs/core/triggers/interface_99_modMyModule_MyTrigger.class.php

Use this to:

  • Send reminders to internal teams

  • Add notes to third-party records

  • Generate reports or log activity

Workflow Example

  1. Invoice validated → wait 10 days → send reminder

  2. Second reminder if unpaid after 20 days

  3. Create task for sales team if unpaid after 30 days

  4. Send internal alert after 40 days to accounting team

This can be configured with custom scripting, or by using workflow modules (available on Dolistore) to build no-code or low-code chains.

11. Integrating with External Reminder Tools (Mailchimp, SMTP, SMS)

Dolibarr can be extended to work with external services to enhance your reminders.

11.1 SMTP Integration

Use a third-party email provider like:

  • Mailgun

  • Sendinblue

  • Google Workspace

  • Outlook SMTP

Why? Better delivery rates, advanced analytics, and bounce tracking.

Configure in:
Setup > Emails > Email Configuration

11.2 Mailchimp / Sendinblue

Export client lists to Mailchimp or Sendinblue for:

  • Branded reminders

  • Open and click tracking

  • A/B testing of messaging

  • Automation with visual workflows

Use the Dolibarr export tools or a Mailchimp connector module.

11.3 SMS Integration

Modules like Twilio SMS, OVH SMS, or custom APIs allow you to send:

  • Payment due SMS reminders

  • Final warnings

  • Receipt confirmations

SMS has high open rates and is ideal for urgent reminders. Modules often include:

  • SMS templates

  • Send history

  • Per-client opt-in settings

12. Best Practices for Reminder Schedules and Messaging

A well-designed reminder system balances firmness and professionalism. Here are common scheduling strategies:

Day Reminder Type Tone
D - 3 Gentle heads-up Friendly and proactive
D + 1 First reminder Neutral, helpful tone
D + 7 Second reminder Slightly firmer
D + 15 Final warning Formal and clear consequences
D + 30 Escalation Possible legal or service freeze warning

Writing Tips

  • Personalize with client names and invoice numbers

  • Keep subject lines clear: "Invoice #12345 - Payment Reminder"

  • Include payment instructions and links

  • Avoid aggressive language; remain professional

  • Always include contact info for questions

13. Avoiding Common Mistakes in Automated Follow-ups

Mistake Solution
Sending reminders for already paid invoices Ensure invoices are marked as paid before reminders run
Using aggressive or rude wording Review email templates with a customer-friendly tone
No opt-out options for marketing-style messages Respect GDPR and email best practices
Forgetting to monitor SMTP failures Enable logging and monitor bounces
Relying on one generic reminder Create multiple templates for different stages

Regularly test your automation flow by simulating overdue invoices in a test environment.

14. Use Cases by Business Type

Freelancers / Consultants

  • Use single email templates and basic cron reminders

  • Helpful for keeping cash flow steady without sounding corporate

SMEs

  • Multiple reminder stages

  • Different messaging for small vs large clients

  • Optionally integrate SMS for higher priority clients

Service Providers (Agencies, IT)

  • Link reminders to support cut-off dates

  • Send soft alerts to customer success teams internally

Retail / E-commerce

  • Fast reminder cycles (e.g., net 7)

  • Integrated with inventory and shipping modules

  • Multi-channel: SMS + email

15. Metrics and Reporting: Measuring the Impact of Automation

Track how your reminders are improving your financial outcomes:

KPIs to Monitor

  • Average time to payment (DSO)

  • Number of reminders sent per invoice

  • Reminder-to-payment conversion rate

  • Client payment reliability scores

  • Reminder engagement (if using email analytics)

Use:

  • Dolibarr’s built-in invoice and payment reports

  • Emailing module stats

  • SMTP provider analytics (Mailgun, Sendinblue)

With data, you can refine frequency, language, and targeting to maximize effectiveness.

16. Final Thoughts and Strategic Recommendations

Automating your client reminders in Dolibarr isn’t just about reducing manual work—it’s about building a more professional, timely, and consistent financial communication process.

Key Takeaways

  • Set up your invoice validation and payment workflows first

  • Use Dolibarr’s built-in features before turning to external tools

  • Create layered templates and schedules for reminders

  • Monitor logs, track metrics, and continuously improve

  • Always balance firmness with professionalism

By combining Dolibarr's native modules, cron jobs, email templates, and third-party integrations, you can create a fully automated, intelligent follow-up system that helps your business maintain strong cash flow without the awkwardness of manual chasing.

17. Additional Resources