Can AI write my overdue invoice reminders?
Yes. It writes polite first, second and final reminders that get you paid without burning the relationship.
01Why bot
- Reminder emails follow a clear escalation pattern.
- AI keeps the tone professional even when you're frustrated.
- You get all three reminders written at once.
Sponsor slot · openFeatured tool for this task. A labeled card for one relevant tool.
Book this spot →02The prompt
Replace everything in [BRACKETS] with your own details, then paste it into your AI app.
Write three payment reminder emails for an overdue invoice. Client: [NAME] Invoice number, amount, due date: [DETAILS] Work delivered: [SHORT DESCRIPTION] How they can pay: [PAYMENT LINK OR METHOD] My late-fee terms (only if in my contract): [TERMS OR "none"] Write: 1) a friendly reminder (3 days late), 2) a firmer follow-up (14 days late), 3) a final notice (30 days late). Each under 120 words, with a clear subject line. Rules: NEVER mention late fees or collections unless I listed terms.
03Steps
- Fill in the invoice details.
- Save the three emails as templates.
- Send each one on schedule.
04What can go wrong
- Only mention fees your contract actually includes.
05What to use
Any major AI chat app: ChatGPT, Claude or Gemini. The free tier works.
06Our test runs
2 runs, each with a different made-up sample. 2 of 2 passed every check.
Run 1 · Llama 3.3 70B · graded by GPT-OSS 120BSep 30, 2026Passed
The made-up sample:
[NAME]Acme Marketing Solutions[DETAILS]Invoice #2026-045, $3,250.00, due September 10, 2026[SHORT DESCRIPTION]Redesign of Acme's corporate website with mobile responsiveness and SEO audit.[PAYMENT LINK OR METHOD]Pay online at https://pay.example.com/invoice/2026-045 or via ACH: Bank XYZ, routing 123456789, account 987654321.[TERMS OR "none"]2% per month on balances overdue more than 30 days.
- Include a clear subject line for each email
- Never mention late fees unless terms listed
- Provide three emails with correct tone (friendly, firmer, final)
- Email 1 under 120 words (51 words, counted by code)
- Email 2 under 120 words (47 words, counted by code)
- Email 3 under 120 words (56 words, counted by code)
- Didn't make up details we never gave it
What came back (excerpt):
This is a final notice for Invoice #2026-045, which is now 30 days overdue. As per our contract, a 2% per month charge will be applied to the outstanding balance.
Read the full answer
Here are three payment reminder emails: 1. Friendly Reminder (3 days late) Subject: Overdue Invoice #2026-045 for Website Redesign Dear Acme Marketing Solutions, We hope you're enjoying your newly redesigned corporate website with mobile responsiveness and SEO audit. This is a friendly reminder that Invoice #2026-045 for $3,250.00 is now overdue. Please pay online at https://pay.example.com/invoice/2026-045 or via ACH to settle your account. 2. Firmer Follow-up (14 days late) Subject: Second Reminder: Overdue Invoice #2026-045 Dear Acme Marketing Solutions, We're following up on Invoice #2026-045 for $3,250.00, which is now 14 days past due. We've delivered the website redesign as agreed. To avoid any further delays, please settle your account online at https://pay.example.com/invoice/2026-045 or via ACH. 3. Final Notice (30 days late) Subject: Final Notice: Overdue Invoice #2026-045 Dear Acme Marketing Solutions, This is a final notice for Invoice #2026-045, which is now 30 days overdue. As per our contract, a 2% per month charge will be applied to the outstanding balance. Please pay $3,250.00 online at https://pay.example.com/invoice/2026-045 or via ACH to Bank XYZ to avoid this charge.
Check that late fees are only mentioned when contract terms allow it.
Run 2 · Llama 3.3 70B · graded by GPT-OSS 120BOct 19, 2026Passed
The made-up sample (a messier one):
[NAME]Acme Widgets Co. (contact: Jane Doe, jane.doe@acmewidgets.com )[DETAILS]Invoice #2023-0479, $4,250.00, due 2023‑09‑15[SHORT DESCRIPTION]Redesign of corporate website, plus SEO setup, content migration, and 2 rounds of revisions.[PAYMENT LINK OR METHOD]Pay via Stripe: https://pay.stripe.com/pay/cs_test_8a9b... or send a check to: 1234 Market St., Suite 500, San Francisco, CA 94103.[TERMS OR "none"]Late fee: 1.5% of the invoice total per month after 30 days.
- Provide three emails with correct timing (3, 14, 30 days)
- Include a clear subject line for each email
- Do not mention late fees unless terms are listed
- Email under 120 words (51 words, counted by code)
- Didn't make up details we never gave it
What came back (excerpt):
Dear Jane, Just a friendly reminder that Invoice #2023-0479 for $4,250.00 is now overdue. We completed the redesign of your corporate website, including SEO setup and content migration.
Read the full answer
Here are the three payment reminder emails: 1. Friendly Reminder (3 days late) Subject: Overdue Invoice #2023-0479 for Website Redesign Dear Jane, Just a friendly reminder that Invoice #2023-0479 for $4,250.00 is now overdue. We completed the redesign of your corporate website, including SEO setup and content migration. To pay, visit https://pay.stripe.com/pay/cs_test_8a9b... or send a check to 1234 Market St., Suite 500, San Francisco, CA 94103. Best, [Your Name] 2. Firmer Follow-up (14 days late) Subject: Second Reminder: Overdue Invoice #2023-0479 Dear Jane, This is a second reminder that Invoice #2023-0479 for $4,250.00 is overdue. We urge you to settle this invoice as soon as possible. Payment options: https://pay.stripe.com/pay/cs_test_8a9b... or check to 1234 Market St., Suite 500, San Francisco, CA 94103. Best, [Your Name] 3. Final Notice (30 days late) Subject: Final Notice: Overdue Invoice #2023-0479 Dear Jane, This is a final notice regarding Invoice #2023-0479 for $4,250.00, which is now 30 days overdue. To avoid any further action, please pay immediately via https://pay.stripe.com/pay/cs_test_8a9b... or send a check to 1234 Market St., Suite 500, San Francisco, CA 94103. A late fee of 1.5% of the invoice total per month will be applied. Best, [Your Name]
Verify the late‑fee mention only appears where allowed.
How each run works: we fill the prompt with a made-up sample, run it once in Llama 3.3 70B, and GPT-OSS 120B grades the answer against the prompt's own rules. Word limits are counted by code, and every quote flagged as made up is checked against the full answer. Your results can differ. How we test.
Ready-made versionFreelancer Client and Invoice Tracker
See inside →Who owes you, how late, and which reminder to send next. Excel + Google Sheets + PDF planner, $16.99.
Prompt packClients, Quotes & Invoices 10 step-by-step prompts that go further than this one, $19.
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