You spend your Sunday evenings retyping line items into a spreadsheet, hunting for the number of your last invoice, and rewriting the same payment reminder email for the tenth time. AI isn't going to do your bookkeeping for you, but it is very good at three things: drafting a clear quote from a three-sentence brief, turning that accepted quote into a complete invoice, and writing payment reminders. Everything else (numbering, totals, VAT, archiving) gets handled by a clean template and a free invoicing tool, not by a €40-a-month subscription.
This guide compares four methods, from the fastest to the most automated, with real costs, honest limitations, and the legal requirements you can't delegate to any language model. You can set the first one up this afternoon, in an hour, with what you already have.
What AI does well on your paperwork, and what it doesn't
AI is excellent at drafting, structuring and chasing; it's bad at calculating, numbering and archiving.
Keep that sentence in mind — it prevents most beginner mistakes. A language model produces plausible text. It doesn't keep a register, it doesn't remember your previous invoice, and it can get a multiplication wrong while sounding perfectly sure of itself.
What AI does very well:
- turn three sentences of brief into a detailed quote, line by line, with labels your client actually understands
- rewrite a vague service (“website redesign”) into priced deliverables (“5-page mockup, build, 1-hour training session”)
- draft the payment terms, the deposit, the number of revision rounds included
- write a firm reminder without being aggressive, in three escalating versions (day 7, day 15, day 30)
- read a confusing client email and pull out the information needed to pre-fill a quote
What you should hand to something other than a prompt:
- the chronological, gap-free numbering of your invoices
- calculating totals, VAT and rounding
- archiving for the legally required period
- exporting to your accountant
The mandatory details are on you
A business-to-business invoice has to include a precise list of information: the name and address of both parties, the SIREN number, the issue date, a unique number, the description and quantity of the services, the unit price excluding tax, the applicable VAT rate, the payment due date and the late-payment penalties. The official list is published on the invoicing page of service-public.fr. Print it out and build it into your document template once and for all. After that, AI fills in the variables, never the legal details.
Second date to keep on your calendar: electronic invoicing is becoming mandatory in France. Every company will have to be able to receive electronic invoices as of September 1, 2026. The obligation to issue them applies to large companies and mid-sized firms on that same date, then to SMEs and micro-businesses on September 1, 2027 (detailed timeline on impots.gouv.fr). In practice: a PDF generated off in a corner and sent by email won't cut it for much longer — you'll have to go through an approved platform. So you might as well get into the habit right now of separating the two roles: AI drafts, an issuing tool produces the official document.
Method 1: producing your quotes and invoices with Skilzy's AI Lab
Skilzy's AI Lab lets you write your quote and invoice prompts, test them immediately on real tools, and keep your templates, without stacking up subscriptions.
Skilzy is a French e-learning platform for learning and using AI. More than 15 programs are available (image, video and music creation, prompt writing, automation with n8n, AI-assisted coding), with a built-in AI Lab where usage credits are included. For paperwork, three building blocks matter to you: the prompt-writing program, the n8n automation program, and Skilzy's Freelance AI program, which starts from the real tasks of an independent worker: prospecting, quotes, invoicing, reminders.
The upside compared with a plain chatbot subscription: you're not paying for three separate tools just to experiment, and you walk away with reusable templates rather than an improvised prompt for every client. Two certifications are state-recognized and eligible for funding: RS7439 (AI content marketing) and RS6792 (AI and sales).
What you build in an hour:
- Your rate card, written down in black and white, service by service. This is the piece 80% of freelancers are missing, and it's what stops AI from inventing prices.
- A quote prompt that takes a brief and outputs a structured table.
- An invoice prompt that picks up the accepted quote and converts it, without touching the amounts.
- Three reminder emails ready to copy, with a tone that escalates gradually.
Here's the skeleton of the quote prompt, to adapt to your needs:
You are my business admin assistant. Using the client brief below, draft a quote in English. Structure: one line of context, then a table of services (label, quantity, unit price excluding tax), then the total excluding tax, then the terms (30% deposit, valid for 30 days, 2 revision rounds included). Do not invent any price or any service: use only my rate card. If something in the brief isn't on the rate card, flag it at the end of the quote instead of pricing it. Brief: [...] Rate card: [...]
Read that instruction again: “do not invent any price.” It's the single most important line in the prompt. Without it, the model fills the gaps with credible but wrong rates, and you end up committing to an amount you never decided on.
Training organizations have a dedicated B2B offer.
Method 2: ChatGPT, Claude or Gemini with a locked-down template
With a clean template document and a precise prompt, the free version of a chatbot is enough to draft your quotes and invoices.
How to go about it:
- Create a single template file (word processor or spreadsheet) containing all the mandatory details, your logo and your terms. You never recreate it.
- In that file, leave clearly named blank fields: client, address, SIREN, service lines, totals.
- Ask the chatbot for the service lines and the text only, never the whole document. You copy, you paste.
- Calculate the totals in your spreadsheet, with formulas. Never in the chat.
- Export to PDF and keep a numbered copy.
The limitations, so you don't discover them on a real invoice: a language model can get a total wrong, mix up amounts excluding and including tax, apply a random VAT rate, or shift a quantity. On a long conversation thread it can also reuse a previous client's name. Check every figure, every time. If you're torn between tools, our comparison of Claude and ChatGPT after six months of daily use goes into the differences on this kind of writing task.
Cost: €0 on the free tier, roughly €20 to €23 a month for a paid plan if you need volume and file attachments.
Method 3: free invoicing tools, for the part AI shouldn't touch
For numbering, compliant PDFs, archiving and payment tracking, a free invoicing tool is more reliable than any prompt.
Several French solutions offer free invoicing for freelancers and small outfits: Henrri, Facture.net, Indy or Tiime on the free side; Abby or Freebe on the paid side, around €10 to €15 a month, with more tracking and payment management. These offers change often, so check the current terms before you commit.
These tools fix exactly the four weak spots of AI: they number without gaps, they calculate correctly, they archive, and they tell you which invoice is unpaid. On the other hand, they're mediocre at writing: you end up typing “Consulting services” across three lines yourself.
Hence the right habit: AI writes the content, the tool issues the document. You generate your service lines with a prompt, you paste them into the software, and you let the software handle the math and the numbering.
| Method | Cost | Setup | What it covers |
|---|---|---|---|
| Skilzy AI Lab | Monthly subscription | about 1 h | Writing, method, automation, fundable certification |
| Chatbot + locked-down template | €0 to €23/month | about 30 min | Writing only |
| Free invoicing tool | €0 | about 20 min | Numbering, PDF, archiving, payment tracking |
| n8n + AI | €0 self-hosted, about €24/month on the hosted version | 1 to 3 days | The whole chain, from brief to reminder |
Method 4: the full automated chain with n8n
n8n connects your form, your AI and your invoicing tool so the quote, the invoice and the reminders go out without you touching a thing.
n8n is a visual automation tool: you connect blocks together without writing code. The typical scenario for a freelancer:
- A prospect fills in a form on your site (project type, budget, deadline).
- n8n sends the form content to an AI model along with your rate card.
- The quote is generated, then you approve it from your phone. That human step is non-negotiable at the start.
- The quote goes out by email, with a signature link.
- Once the signature comes back, n8n creates the invoice in your invoicing tool and sends it.
- No payment by day 7? The first reminder goes out on its own. Then day 15, then day 30.
Budget a weekend to build this properly the first time, less if you start from an existing template. The real payoff is less about the time saved than about the reminders: those are the ones you never send, and they're the ones that unlock your cash flow. To go further on the overall logic, read our practical guide to automation with AI for entrepreneurs, and for the sending and tracking side, our article on automating emails with AI.
One warning: never hook up an automation that sends financial documents without human approval until you've watched it run correctly twenty times in draft mode. A wrong quote sent automatically is a contractual commitment.
Key takeaways
Start small: one clean document template, a written rate card, two prompts. You're already getting back two to three hours a month and you stop putting off your reminders. Add a free invoicing tool for numbering and archiving, since mandatory electronic invoicing is coming in 2026 and 2027. Full automation with n8n can come later, once those first two building blocks run without surprises. And in every case, stick to the basic rule: AI writes, you check the figures.
