# Find out who really sent a mystery bill or notice

> A notice with only a reference number got traced back to the original company by searching the inbox for that ID.

Give ChatGPT the reference number from a confusing notice and let it search your Gmail. You get the original company, the matching emails and a short list of what to check next.

- Page: https://thesolocreators.com/prompts/find-who-sent-a-mystery-notice/
- Category: Handle life admin fast
- Made for: Everyone
- Works in: ChatGPT, Gemini, Gmail
- Time: About 5 minutes
- Effort: A few steps
- Note: Needs Gmail connected in ChatGPT or Gemini. Never share bank or card details with an unconfirmed sender.
- Published: 2026-10-26

## How do I find out who sent a bill with only a reference number?

Connect your email to an AI assistant and ask it to search for the reference number, the amount and similar account numbers, then name the original company. Use ChatGPT if your Gmail is connected there through Apps, or Gemini if you already use its Gmail extension (as of October 2026). If nothing matches, treat the notice with extra care and ask the sender to confirm the original company and amount in writing before you pay anything.

## The prompt

Fill in the parts in [square brackets], or leave them and the AI will ask you for them.

```text
I got a confusing notice and I don't know who it's really from. Here's what it shows: reference number [REFERENCE NUMBER, e.g. 88412-B], date [NOTICE DATE, e.g. October 14], amount [AMOUNT DUE, e.g. 86.40] and sender name [SENDER NAME, e.g. Recovery Services Group]. Search my email for that reference number, the amount, and any account or order numbers that look similar. Tell me: 1) which company the original account or purchase was most likely with, and the emails that prove it, 2) when the last bill or receipt from them arrived, 3) anything that doesn't match, like a different amount or a sender I've never dealt with. Then list 3 things I should check before paying or calling anyone, and draft a short, polite email asking the sender to confirm the original company, the amount and what it covers. Don't guess. If you can't find a match, say so plainly.
```

## Step by step

1. Connect Gmail in ChatGPT (Apps) or turn on the Gmail extension in Gemini.
2. Type the reference number, date and amount from the notice into the prompt below.
3. Paste the prompt and let it search your inbox.
4. Read the matches and use the draft email to ask the sender for details.

## What you'll get

The company the notice most likely traces back to, the emails that show it, any mismatches, and a polite email asking the sender to confirm the details.

## Good to know

**How do I find out who sent a bill with only a reference number?** Connect your email to an AI assistant and ask it to search for the reference number, the amount and similar account numbers, then name the original company. Use ChatGPT if your Gmail is connected there through Apps, or Gemini if you already use its Gmail extension (as of October 2026). If nothing matches, treat the notice with extra care and ask the sender to confirm the original company and amount in writing before you pay anything.

**Which AI tools does this work in?** It works in ChatGPT, Gemini and Gmail. On this page, ChatGPT opens with your prompt already typed in. Needs Gmail connected in ChatGPT or Gemini. Never share bank or card details with an unconfirmed sender.

**How long does it take?** About 5 minutes. It's rated "A few steps". There are 4 steps, listed above.

**What do I need before I start?** Just your details for 4 blanks: reference number, notice date, amount due and sender name. You can skip any, and your AI will ask for them.

**What will I get back?** The company the notice most likely traces back to, the emails that show it, any mismatches, and a polite email asking the sender to confirm the details.

Idea spotted on Reddit, shared by u/HeavyMetal_Protein: https://www.reddit.com/r/ChatGPT/comments/1xazbqc/. The prompt is The Solo Creators' own version.

## Go further

Ready-made skills in the Solo Creators AI Studio (https://thesolocreators.com/studio/) that fit this: TLDR (Your AI stops writing walls of text: every reply leads with the next action, numbered and skimmable); Second Brain (Give your AI a memory it reads across every project, so it finally knows your business).

From AI Use Cases and Prompts by The Solo Creators: https://thesolocreators.com/prompts/. Free to use; please link back to the page when you share it.