How to Create Invoices with Claude and ChatGPT

You can create real invoices with Claude or ChatGPT by connecting them to KipBill. Add the connector address https://kipbill.com/mcp in Claude (Customize → Connectors) or in ChatGPT (as a custom MCP server), sign in to KipBill and press Allow. From then on you can type "invoice Nomad Studio for 10 hours of design at $45 and send it", and the invoice is made in your KipBill account with your numbering, your taxes and your template.

It takes about two minutes, it works on every KipBill plan (Free included), and the AI runs on your own Claude or ChatGPT plan. This guide shows every step with real screenshots, then what you can ask and how your data stays under your control.

Here is what it looks like once it's connected: one sentence in the chat, the app asks for your OK, and KipBill does the rest.

What you need

• A KipBill account with your business set up. The free plan is enough. If you don't have one yet, the connection screen lets you create it for free and come straight back.
• Claude on any plan, Free included (Free allows one custom connector), or ChatGPT on a plan or workspace that lets you add your own MCP servers.
• Two minutes. There are no API keys to copy and nothing to install.

Connect KipBill to Claude

These steps work in Claude on the web and in the desktop app. Once added, the connector is also available in Claude's phone apps.

1. Copy the connector address in KipBill

   In KipBill, open Settings → Integrations. Under Claude and ChatGPT you'll find the connector address and the steps for each app. You can also copy it right here:

   Connector address

   https://kipbill.com/mcpCopy

   kipbill.com/en/dashboard/settings

   

2. Add a custom connector in Claude

   In Claude, open Customize → Connectors and choose Add custom connector. Type KipBill as the name, paste https://kipbill.com/mcp as the URL and press Add. Then press Connect next to KipBill.

   

   On Claude Team and Enterprise, an owner first adds the connector for the organisation in Organization settings → Connectors; then each person connects their own KipBill account.

3. Sign in to KipBill and press Allow

   KipBill opens in your browser and shows exactly what Claude will be able to do. If you have several businesses, pick the one Claude should work with (you can ask for another later). Leave Also allow creating and sending ticked to create and send from the chat, or untick it so Claude can only look things up. Then press Allow.

   

   Not signed in yet? The same screen lets you sign in, or create a free account and set up your business in about a minute, and then brings you back here.

4. Check it in Settings → Integrations

   Back in KipBill, Settings → Integrations now lists Claude under Connected apps: which business it works with, whether it can create and send, and since when. Disconnect stops it at once.

   

That's it. Open a new chat in Claude and ask away.

Connect KipBill to ChatGPT

1. Add KipBill as a custom MCP server

   Open chatgpt.com/plugins, press + and add a custom MCP server. Paste https://kipbill.com/mcp as the connection, create it as a plugin and install it.

   Adding your own MCP servers depends on your ChatGPT plan and workspace settings. If you don't see the option, your plan or your workspace admin doesn't allow it yet.

2. Sign in to KipBill and press Allow

   ChatGPT opens KipBill's connection screen. Check what it will be able to do, choose the business and press Allow.

   

3. Use it in a chat

   In a chat, type @ and choose KipBill, then ask what you need. Settings → Integrations in KipBill lists ChatGPT next to your other connected apps.

Claude Code and other MCP apps

Developers can add the same connector to Claude Code with one command:

claude mcp add --transport http kipbill https://kipbill.com/mcp

Then type /mcp in Claude Code, choose kipbill and sign in. Any other app that supports remote MCP servers with OAuth sign-in connects the same way: give it the address and approve it on KipBill's screen.

What you can ask

The connector works on your real KipBill data: the same clients, prices, taxes and numbering as in the app. Ask in plain words, in your own language. Copy any of these to try them:

Every answer includes a link to the document in KipBill, where you can review it, download the PDF or edit anything before sending.

Why connect instead of asking ChatGPT to "make an invoice"

Ask a chatbot for an invoice and you get text that looks like one. The number is made up, the taxes are whatever you typed, and nothing is saved anywhere. Connected to KipBill, the same request becomes a real invoice in your books:

Prefer not to connect anything? Try the free AI invoice generator: describe the invoice in one sentence and download the PDF, no account needed.

What it can and can't do

• It asks you first. Claude and ChatGPT ask for your OK before using a tool that changes your data, unless you've told them to always allow it.
• New documents start as drafts. Invoices and quotes are created as drafts with your next number; they are emailed only when you ask.
• It never deletes or moves money. The connector can't delete documents, move money, or change your settings or your plan.
• Your plan's limits apply. Free includes 5 clients and 10 emails a month; payment reminders need the Starter plan or higher. When a limit stops something, the reply says which one.
• Team roles stay the same. Each person connects their own KipBill account: an editor can create and send, a viewer can only look things up.
• Not yet: credit notes, recurring invoices, expenses and settings. For those, use the app.

Privacy and security

• You sign in on kipbill.com. Claude and ChatGPT never see your password. The connection uses OAuth 2.1 with PKCE, the sign-in standard of MCP.
• KipBill gets requests, not your conversation. It sees, for example, "find the invoices of Acme Corp" and answers with those invoices, nothing else.
• Tokens are kept as fingerprints. KipBill stores only a hash of each access key, never the key itself. Keys last one hour and renew in the background.
• Disconnecting is instant. Settings → Integrations → Disconnect cancels the app's access at once.
• The rest is up to the AI app. What Claude or ChatGPT do with the answers follows their own privacy terms and your settings there.

Troubleshooting

"The app that sent you here isn't registered with KipBill." The sign-in link is out of date. Go back to Claude or ChatGPT and press Connect again: a fresh link fixes it.

Claude doesn't let you add another connector. Claude's Free plan allows one custom connector. Remove one you no longer use, or use a paid Claude plan.

You can't find "Add custom connector" at work. On Claude Team and Enterprise, an owner adds it first in Organization settings → Connectors.

ChatGPT has no option to add an MCP server. Your ChatGPT plan or workspace doesn't allow custom servers yet. Your workspace admin can tell you.

It can look things up but not create. "Also allow creating and sending" was unticked when you connected. Disconnect it in Settings → Integrations and connect again with the box ticked.