Invoice reminder automation: getting paid without the awkward call

Invoice reminder automation sends a polite message before an invoice falls due, another when it is overdue, and a task to a person when it stays unpaid, so nobody has to remember who owes what or make the awkward call. Done well, the customer gets a clear prompt with a way to pay, and you only step in for the accounts that need a human.

This guide covers the trigger, the timing, the wording and the checks a person still does. It assumes you already send invoices from accounting software such as Xero or MYOB. If you are still chasing by memory, start here.

What the automation actually does

An automated payment reminder is a short chain of steps. Written down, it looks like this:

1. Trigger. An invoice is approved and sent, so the system records the due date and the amount owing.
2. Wait. The workflow sits idle until a set number of days before or after the due date.
3. Check. Before every message it asks the accounting software: is this invoice still unpaid, and is it flagged as disputed or on hold?
4. Send. If it is still unpaid and not on hold, the right message goes out by email, and by text for the later stages.
5. Escalate. If the invoice is still open after the last message, it creates a task for a named person and stops sending.

The check in step three is the one that matters most. A reminder that arrives the morning after the customer paid is worse than no reminder, because it tells them you are not looking at your own books.

Check your accounting software first

Many accounting packages already have built-in reminders that email a customer a set number of days before or after the due date. If yours does, switch that on first. It reads straight from the invoice, so it cannot get out of step with payments, and it costs nothing extra to try. Check your provider’s help pages for what yours can do and which plan includes it.

Built-in reminders usually fall short in three places: they email only (no text), they send the same wording to every customer, and they do not create a task for a person when an invoice is still open. If those gaps cost you money, a separate workflow is worth building. If not, leave it alone. Our guide to Xero automation for small business covers what else can be connected.

An invoice reminder automation schedule for most small businesses

There is no single correct number of reminders. This schedule is a sensible starting point for 14 or 30 day terms. Adjust it to your payment terms and your customers.

Sending before the due date feels strange at first. It works because many late payments are simply forgotten, not refused, and a note with a pay link removes the excuse that the invoice got buried.

Sample wording for each stage

Keep each message short, put the amount, invoice number and due date in the first lines, and always include a way to pay. Here are four you can adapt.

Before the due date:

Hi [First name], a quick note that invoice [number] for $[amount] is due on [date]. You can pay online here: [link]. If you have already paid, thank you, and please ignore this message.

Seven days overdue:

Hi [First name], invoice [number] for $[amount] was due on [date] and hasn’t come through yet. Here is the link to pay: [link]. If something is holding it up, such as a query about the invoice, just reply to this message and we will sort it out.

Fourteen days overdue:

Hi [First name], invoice [number] for $[amount] is now 14 days past its due date of [date]. Please pay by [date] using [link], or reply to let us know when we can expect payment. If there is a problem with the work or the invoice, tell us and we will look at it straight away.

The text version, kept to one message:

[Business]: invoice [number] ($[amount]) is overdue. Pay here: [link]. Already paid or have a question? Reply to this text.

Notice what the messages leave out. They do not accuse, they do not threaten, and they always offer a reply path. A customer who is disputing the work will respond to the invitation to talk. A customer who has simply forgotten will pay. Both outcomes beat silence.

Where a person steps in

Automation should handle the routine. A person should handle anything that carries relationship risk or a dispute. Decide these rules before you switch it on:

• Hold list. Customers who are disputing an invoice, on a payment plan or in a sensitive situation are tagged, and the workflow skips them.
• Large invoices. Set a dollar amount above which the workflow creates a task for a call instead of sending the fourteen day message.
• Key customers. Your five biggest accounts may deserve a personal message from the owner at the first overdue stage.
• Replies. Any reply to a reminder lands with a named person, not in a no-reply inbox. A reply of “paid last week” needs a human to check the bank feed.

For a trades business, this often means the office manager owns the task list and the owner only sees accounts past 21 days. See our guide on how tradies get paid faster for the steps before the invoice goes out, such as deposits and clear terms.

The checks that keep it from embarrassing you

Most failures come from a short list of causes. Test for each one before you go live:

1. Paid but still chased. Take five invoices you know were paid and confirm the workflow does not pick them up. Payments can take a day or two to match to invoices, so add a short grace period before the first overdue message.
2. Wrong contact. The reminder goes to the email on the customer record. If the invoice was meant for accounts but the record holds the site contact, the message lands with the wrong person.
3. Part payments. If a customer paid half, the message should show the balance owing, not the original total.
4. Credit notes. An invoice that has been credited should drop out.
5. Duplicates. If two systems both send reminders, the customer gets two. Switch one off.

Run it in a quiet mode for the first two weeks. Have the messages sent to you instead of customers, and read them. This is the cheapest test you will do. Workflows also break when a tool changes something behind the scenes, so see why automations break and put a monthly check in the diary.

Fees, interest and the rules around chasing debts

Do not add a late fee or interest to a reminder unless it is in your written terms and the customer agreed to them. Rules on late payment charges, and on how and when you may contact someone about a debt, differ by country and sometimes by state, and they change. Check with your accountant or the relevant regulator before you write a reminder that mentions a fee, a collections agency or legal action. The ordinary reminders above ask for payment and nothing more, which is the safe approach.

Text messages that go to customers also fall under spam and marketing rules in some countries. Our summary of SMS marketing rules in Australia is a starting point, and the Australian Communications and Media Authority publishes the rules themselves. Check them for your situation.

What it looks like when it is set up well

Picture a plumbing business with a part-time office manager. Invoices go out from the accounting software on the day the job closes. The workflow reads each new invoice, waits until three days before due, checks the status, and sends the first note with a pay link. Customers who pay never hear from the business again. The few who reach 21 days appear in a short list on Monday morning, and the office manager rings them, because a phone call from a person who knows the job gets a different answer than a fifth email.

CentriWeb builds most client automations in n8n, and for invoice reminders the build is small: a connection to the accounting software, the schedule above and the task list. We can also build and look after the whole workflow if you would rather not, but if your accounting package’s own reminders already do the job, use them.

A short plan to start this week

• Write your payment terms in one sentence and put them on every invoice.
• Switch on your accounting software’s built-in reminders and watch them for a month.
• List your overdue invoices today and note which were forgotten and which were disputed. That ratio tells you how much a person is needed.
• Draft the four messages above in your own words.
• Decide who owns the 21 day task list, and give them the time to work it.

Pair this with a clear process for recurring payments for customers who pay every month, since an automatic card payment removes the need to chase at all.