Guide / ChatGPT
How to invoice a client from ChatGPT.
The short answer
Connect once, then invoice from any ChatGPT chat. In ChatGPT on the web, open Settings, then Apps, turn on Developer mode under Advanced settings, and create an app with the server address https://www.ihateinvoicing.io/api/mcp. Sign in and approve access, then select I Hate Invoicing from the tools menu in a new chat and say: bill Acme $500 for design work Tuesday. ChatGPT drafts the invoice with a PDF and a payment link. You approve it. It sends.
Working in Claude instead? See the Claude guide.
No job left unbilled. Send invoices from inside Claude and ChatGPT. No monthly fee.
01 / Connect
Four lines, one time.
- LINE 01
Open Settings, then Apps
In ChatGPT on the web, open Settings, then Apps, then Advanced settings, and turn on Developer mode. - LINE 02
Create the app
Choose Create, pastehttps://www.ihateinvoicing.io/api/mcp, select OAuth, and choose Scan Tools. - LINE 03
Approve access
Sign in to I Hate Invoicing and approve the connection, then finish creating the app. No API keys to copy, nothing to store. - LINE 04
Say the sentence
In a new chat, select I Hate Invoicing from the tools menu and say:bill Acme $500 for design work Tuesday. Review the draft, approve it, and it sends.
02 / What happens
One sentence in, a sent invoice out.
A professional PDF
Line items, rates, dates, and totals on a clean invoice PDF with your details and your client's.
A Stripe payment link
The client pays by card from the link in the invoice email. The money lands in your Stripe account.
The email to your client
The invoice email goes out after you confirm the draft. Until you approve, nothing sends.
Tracking until paid
See what is still unpaid, send automatic reminders, and ask ChatGPT for the aging report in plain language.
03 / Past the first invoice
The chat keeps your books.
Client billing rules
Save each client's rate, minimums, mileage, cancellation policy, and Net terms once. Every invoice applies them, with the math shown before anything sends.
Built for agency work, including interpretersWho owes you
Open invoices by client, aged 1-30, 31-60, and 60+ days. Ask ChatGPT who is late and get the aging report in the chat.
Year-end 1099 tracking
Paid totals per client, flags at the $600 1099-NEC threshold, and a tax set-aside estimate you can ask for any time.
04 / Pricing
Free. Actually free.
No subscription, no invoice limits, no trial clock. You pay 5.9% + $0.59 only when a client pays through Stripe, so we make money when you do.
See the pricing pageCommon questions
Does it work on the free ChatGPT tier?
I Hate Invoicing is free no matter which ChatGPT plan you use. Whether a plan includes custom MCP apps is set by OpenAI and can change, so check the current plan details in ChatGPT under Settings, then Apps.
Is this in the GPT store?
No. It is not a GPT and there is nothing to install from a store. You add the I Hate Invoicing server yourself under Settings, then Apps, with the server address on this page.
Can ChatGPT send an invoice without my approval?
No. ChatGPT can draft and preview invoices, but drafts never send on their own. Every send needs your explicit confirmation in the chat, right before it goes out.
Is it really free?
Yes. There is no subscription, no monthly fee, and no invoice limit. You pay 5.9% + $0.59 only when a client pays an invoice through Stripe.
What data can the connection see?
Only your I Hate Invoicing account, through OAuth. You approve the access scope when you sign in. It never sees your Stripe credentials, and you can revoke access any time from your I Hate Invoicing settings or by deleting the app in ChatGPT.
Does it work with Claude too?
Yes. The same account connects to Claude with the same server address. The Claude guide on this site walks through that setup.
No job left unbilled
Your next invoice is one sentence away.
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