To send invoice reminders to your customers, you'll first need to look for the invoice, log into a messaging platform, write a text message, and send it to the customers.
This is the manual way, but with Peakflo, you can simplify the process with fewer clicks!
1. First, go to Invoice and click on the invoice you'd like to send to the customer.
2. Click on the three dots at the top right, and once the options pop out, click Send Email or Send SMS – depending on the mode of communication you'd like to use. 
3. Let's say, if we choose Send Email, you can easily add a recipient alongside CC and BCC as well as customize the subject and the message or use a pre-made template.
Learn how you can customize: How can I customize my workflow action template with placeholders?
If you want to include invoice as an attachment, you can tick the box.
Once you're sure, hit Send.
4. Now, let's go to Send SMS. The process is similar to Send Email – add a recipient, write a new message or use a pre-made template.
Once you've done and checked, hit Send SMS.
All of your communications will be recorded in the Invoice Timeline, which you can also export by clicking on the three dots at the top right and choose Export timeline.
📖 Related article: How to track the customer queries and replies?