A small business or an accounting practice still gets invoices, statements, signed forms and tax papers by fax, and someone has to open each one, key the figures in and chase whoever has not sent theirs. With Claude or ChatGPT connected to Fax.Plus through MCP, that becomes a routine: one word gives you the morning summary, another reads invoices into ledger rows, a third shows who has not sent their documents, and a Friday word writes the week up. Below is the process, how to set it up once, and example results with simulated documents and fictional parties.
Everything here is an example. Change the prompts, the order and the times to fit how you work; nothing is set in stone.
Before you start
- Use an active Fax.Plus Basic plan or higher and an existing authorized Fax.Plus MCP connection.
- MCP is unavailable for accounts with Advanced Security Controls, including HIPAA and PHIPA configurations.
- For the missing-documents check, have a list of who you expect documents from.
- Use job or client codes, not names, in prompts and comments where you can.
Not connected yet? Start at the Fax.Plus MCP setup hub.
The process
Faxing is one step in a longer process. The steps marked Fax.Plus MCP are what the Fax.Plus connector does. The steps marked Optional are examples of other connectors you may already use: any connector you have set up in Claude or ChatGPT can be a step in your process, and the Fax.Plus connector is simply one part of it. The connectors do not talk to each other and Fax.Plus does not pass data to them: the assistant carries the information from one step to the next inside the same chat, because you told it to, and it asks for your OK before it changes anything. Whether an optional step works depends on your AI client and that connector.
- Fax.Plus MCP: your received faxes are read and summarized: what each one is, how many pages, and whether it needs action.
- Fax.Plus MCP: invoices and statements are read into rows: supplier, invoice number, date, amount and due date, exactly as written.
- Optional, for example Google Sheets: the rows go into your ledger or your accountant's sheet, after your OK.
- Fax.Plus MCP: your list of expected senders is compared with what has arrived, and who is still missing is shown.
- Fax.Plus MCP: each fax gets its client or supplier code as a comment, after your OK.
- Optional, for example Slack or Gmail: a short weekly summary is drafted for your partner or team; you review it before it goes out.
Set it up once
Instead of pasting the rules into every chat, keep them where every chat can use them, so that one word starts a routine. The prompts are the same in Claude and ChatGPT; the setup steps differ a little.
- Connect Fax.Plus. In Claude, add it under Settings → Connectors. In ChatGPT, add it as a custom MCP app: turn on Developer mode, then go to Plugins → Browse plugins, select +, then Create app → Create MCP App, and sign in with your Fax.Plus account. Step by step: Claude and ChatGPT. Connect any other connectors you use the same way.
- Keep the instructions in a Project. Create a Project in Claude or ChatGPT, name it after the desk, for example "Fax butler", and paste the instructions below into the project's instructions, filling in the parts in [brackets]. If a connector does not show up inside a project chat in your client, open a regular chat instead and paste the instructions as your first message.
- Start a chat, make sure Fax.Plus is selected for it (in ChatGPT, choose FaxPlus from the apps or type @), and type a routine name. The assistant runs the steps and stops at every change for your OK.
- Edit the instructions whenever the routine should change.
Interface labels and plan availability differ between clients, so check the current screens in yours.
Fax butler instructions
You are my fax butler for my Fax.Plus account. Rules: 1) Refer to clients and suppliers by the codes I give you where I have given one. 2) Before you change anything, such as a comment or a read status, show me exactly what will change and wait for my OK. 3) Read figures, dates and invoice numbers exactly as written on the page and say so if one is missing. Never approve, pay or dispute an invoice and never tell me to. 4) Leave out fax numbers unless I ask. 5) Never send, resend or delete a fax unless I ask for it in that message. 6) If something fails, tell me what failed and check the current state before trying again. Routines, run one when I type its name. MORNING: show my received faxes from the last 24 hours, one line each: date, pages, what it is, and whether it needs action. LEDGER: read the invoices and statements among my newest received faxes into one table: supplier, invoice number, invoice date, amount with currency, due date; say so if a field is missing; change nothing. MISSING [list of expected senders]: compare my received faxes from the last 30 days with the list; for each name say whether a fax has arrived, with its date, and list who is still missing; say what each page shows and do not guess. TAG [code]: add the code as a comment to the received fax I point to, after showing me the change and getting my OK. FRIDAY: summarize the week: how many faxes arrived, how many I sent, which need follow-up, who is still missing; write it as a short message I can review; do not send it.
MORNING: what arrived overnight
Type MORNING. Example result for three simulated faxes: an invoice from a supplier (2 pages, needs action), a signed engagement letter back from a client (1 page, filed), and a bank notice (1 page, needs a look). The assistant lists each with date, pages and what it is. Reading is read-only. Guide: Find and read a received fax.
Morning summary
Show my received faxes from the last 24 hours, one line each: date, number of pages, what it is and whether it needs action. Leave out sender numbers. Do not change anything.
LEDGER: invoices into rows
Type LEDGER. Example result for two simulated invoices: Northwind Supply (fictional), invoice 10432, dated October 8, 2026, USD 1,280.40, due November 7, 2026; Harbor Print (fictional), invoice 2207, dated October 9, 2026, USD 342.00, due November 8, 2026. The figures are written exactly as on the page, so check them against the original before they go into your books.
Invoices into rows
Read the invoices among my newest received faxes into one table: supplier, invoice number, invoice date, amount with currency and due date, exactly as written. Say so if a field is missing. Do not change anything.
MISSING: who has not sent their documents
Type MISSING with your list. The assistant compares the list with your received faxes and says, for each name, whether a fax has arrived and when. It can only see faxes that came in through Fax.Plus, not documents that arrived by another route.
Who is missing
I expect documents from [name], [name] and [name]. Compare my received faxes from the last 30 days with this list. For each one say whether a fax has arrived and its date, and list who is still missing. Say what each page shows; do not guess.
TAG: file it under the client or supplier
The assistant shows which fax it would change and writes the code into the comment after your OK, then reads it back. Guide: Keep your fax inbox tidy.
Tag with a code
Add the comment [client or supplier code] to my newest received fax. Show me which fax you will change and wait for my OK, then read it back to confirm.
FRIDAY: the weekly summary
Type FRIDAY. The assistant writes a short summary of the week; you review it and send it yourself, or have another connector draft it.
Weekly summary
Summarize my fax week: how many received faxes arrived, how many I sent, which need follow-up and who is still missing from [list]. Write it as a short message I can review. Do not send anything.
Keep it safe
- Never act on a change of bank details or payment instructions that arrives by fax without confirming it by phone, using a number you already have. A fax is not proof of who sent it.
- The assistant reads what the page says. Whether to approve, pay or dispute an invoice is your decision.
- Documents you open are read by your AI assistant under that client's terms. Check your own policy on client data first.
- Prompts that change your records ask the assistant to show you the change and wait for your OK. Whether your client also asks for approval depends on its permission settings, so keep the Fax.Plus tools that send or change data on the setting that asks first.
- If a reply looks wrong, do not assume nothing happened. Check the outbox and sent faxes before you try again.
Related guides
Find and read a received fax and keeping your inbox tidy cover the steps above. More prompts are in Fax Prompts with AI, recurring checks in Fax Automation with AI.
