How to make an invoice in 15 seconds: forward your client's email, done

The monthly ritual we all accept

Marta is a freelance designer in Barcelona. She invoices 3-4 clients a month. One writes: "Marta, can you send me August's invoice? €900 for the landing page redesign." The ritual starts:

1. Open Word and hunt for last year's template.
2. Copy the client's tax ID from an old email.
3. Type the description.
4. Compute the VAT (calculator, reluctantly).
5. Save as PDF.
6. Reply by email.

8 minutes per invoice. 4 invoices a month. 32 minutes she resents. Then the quarter. Then the year.

Billy does that ritual in 15 seconds

Now imagine Marta does ONE thing: forwards her client's email to marta@askbilly.net (her personal Billy address, picked at signup).

Within 15 seconds, an invoice appears in her Billy inbox, already drafted with:

• The client's details — name, tax ID, address — pulled from the email or the contacts database.
• The description exactly as the client asked: "€900 for the landing page redesign."
• VAT computed with the right rate for the client (domestic 21 %, EU intra-community 0 %, export with exemption…).
• Her next sequential invoice number for the month.
• The VeriFactu record already chained by SHA-256 fingerprint.

She opens it, reviews (2-3 seconds: amount right, client right, done), approves. The invoice comes out with a verification QR and would be ready to submit to the tax agency if auto-submit were enabled (or to download as PDF and attach to her reply).

What happens under the hood

Three steps in the back office when you forward the email:

1. Understanding (AI). A language model reads the message and extracts what needs invoicing: client, concept, amount, currency, whether they asked with or without VAT. It also detects whether the client already exists or is new.
2. Verification (deterministic code). Billy computes base, VAT and withholding per the client's rules. No tolerances — if a total doesn't match to the cent, the proposal is rejected and the AI is re-run with more context. Numbers that are "approximately right" are never silently accepted.
3. Draft. The invoice appears in your inbox as "pending approval". Nothing is sent without your confirmation. The copilot only creates drafts; approving and numbering stays your decision.

What if the email is missing information?

Sometimes the client just writes "please send me this month's invoice" without more. Billy tries with what it knows:

• If the client is already in your base and you invoice something recurring, it drafts that and flags it as suggested, review before approving.
• If a required field is missing (the amount, for example), it drafts what it can and highlights in red what still needs filling in. One click and you type it.
• If the client isn't found, it creates a draft contact and enriches automatically via VIES / commercial registry. You approve.

Never silent failure. Always asks or flags.

What it saves you per year

• 4 invoices × 8 min × 12 months = 6 hours a year of copy-paste.
• 20 years as a freelancer = 120 hours.
• 3 full days of your life on tasks a forwarded email would resolve.

The point isn't that the AI is fast. The point is that you can trust what it produces without re-reading it.

Try it with your next invoice

Billy has a free plan with up to 25 invoices per year — enough to see if forward-to-invoice works with your real clients. The Pro plan is €9/month with unlimited invoices and everything Billy does included. No card to start, no sales calls, no lock-in.

Next time a client asks for an invoice, don't open Word. Forward the email to your Billy address and count the seconds.