AI prompts to chase unpaid invoices politely

Steps

1. 1

   Pull the facts first.

   Get the invoice number, amount, due date, days late, and anything the customer said about it. The AI can only be as right as what you give it.

2. 2

   Pick the stage.

   Is this the first nudge, the second reminder, or the last one before you call or pause work? Tell the AI which one, because the tone should change.

3. 3

   Paste a prompt below and fill the brackets.

   Use ChatGPT, Claude, Gemini or Copilot. Any of them can write this well if the facts are in the prompt.

4. 4

   Check every number.

   AI can mix up dates and amounts. Match the draft against your invoice line by line.

5. 5

   Send it from your normal email.

   Then note the date you sent it so you know when the next reminder is due.

Prompts you can copy

First friendly reminder

You are helping me write a payment reminder to a customer I want to keep.
Customer: [company name], contact [first name].
Invoice: [invoice number], [amount], due [date], now [number] days late.
What I know: [anything they said, or "nothing yet"].
Write a short email, under 80 words. Friendly, plain words, no guilt. Assume it slipped through the cracks.
End with one question asking them to confirm a payment date.
Give me a subject line too.

Second reminder, a bit firmer

Write a second payment reminder. The first one went out on [date] and got [no reply / this reply: ...].
Customer: [company], contact [first name]. Invoice [number], [amount], due [date], now [number] days late.
Tone: polite but clear. Say the amount and how late it is. Offer to resend the invoice or take payment by [payment method].
Under 90 words. End with one question that asks for a date.
Do not threaten anything I have not told you about.

Final notice before a call or a hold

Write a final reminder email for an invoice that is [number] days late.
Customer: [company], contact [first name]. Invoice [number], [amount].
Our terms say: [paste the late terms from your contract, or write "none"].
Next step if unpaid by [date]: [I will call you / we will pause new orders / other].
Tone: calm and firm, not angry. Under 100 words.
Only mention the next step I gave you. Ask them to reply with a payment date.

Reply when they say they cannot pay yet

My customer replied about a late invoice. Here is their reply: [paste it].
Invoice [number], [amount], [number] days late.
I am open to: [a payment plan of X / a short delay to date / nothing, full amount needed].
Write a kind, short reply that thanks them for answering and proposes [option].
Under 80 words. End with one question to lock in the plan.

Example

This is a made-up example. Say you fill in the first prompt with: Customer Harbor Supply, contact Dana, invoice 1042 for $2,350, due October 1, now 21 days late, no reply yet.

A good answer looks like this:

Subject: Invoice 1042

Hi Dana, hope your week is going well. Invoice 1042 for $2,350 was due October 1 and I don't show a payment yet. It may have slipped through, it happens. Happy to resend it if that helps. Can you let me know what date you plan to pay it?

It is short, it says the facts, and it asks one question. That is what you want.

Tips

• Keep the facts at the top of the prompt. The AI copies numbers better when they are clear and in one place.
• Ask for two versions if the first sounds stiff, then pick the one that sounds like you.
• If you have a real relationship with the person, tell the AI. "We have worked together for five years" changes the tone in a good way.
• Save the prompt that works best so your next reminder takes one minute.

What not to do

• Do not let the AI invent late fees, interest or legal steps. Only include terms that are in your contract.
• Do not paste a customer's bank details or card numbers into an AI tool. Check your company rules on what you can share.
• Do not send without reading it. One wrong amount makes the whole email look careless.

For more ready prompts on this, see late payment prompts and invoice prompts. If you do the books, the bookkeeper prompts page has more.

FAQ

Will an AI reminder sound rude?

Not if you tell it the tone. Say "friendly, assume it slipped through the cracks" for the first one and it will stay polite.

Can I use this in Outlook or Gmail?

Yes. Write the draft in any AI tool and paste it into your email. Some plans of Copilot in Outlook and Gemini in Gmail can also draft right inside the email app.

How many reminders should I send?

That depends on your business and your terms. A common pattern is a friendly nudge, a firmer reminder, and then a phone call. A call often gets a date faster than another email.

Should the AI write the final legal letter too?

No. For anything legal, like collections agencies or demand letters, talk to your accountant or a lawyer. Use AI for the everyday reminders.

Rather have it done for you? We build the system that handles your outreach, one time, and you own it. See how it works.

First posted October 28, 2026. Last updated October 28, 2026. Free to copy and use, CC BY 4.0.