Electronic Invoices for Flat-Rate Taxpayers — Obligations, Deadlines, and How to Issue Correct e-Invoices

Are you a flat-rate taxpayer (regime forfettario) in Italy? Until recently you could send paper or PDF invoices. Now the electronic invoice (fattura elettronica) is mandatory for everyone, including forfettari. The problem: many professionals face fines or rejected invoices because of simple mistakes. Here we explain exactly what you need to know, with the same practical approach we use for our clients at Meteora Web.

What changes for flat-rate taxpayers with mandatory e-invoicing?

Since July 1, 2022, the obligation applies to all VAT-registered taxpayers, including those in the flat-rate regime. No exceptions for low turnover or private customers. If you issue an invoice, it must be electronic. Only point-of-sale receipts (scontrini) are exempt.

We've seen forfettari still sending PDFs via email, facing penalties from €100 to €1,000 per wrong invoice. Don't be one of them.

The SDI is not a monster

The Sistema di Interscambio (SDI) is a simple gateway: you send an XML file, it checks formal correctness and forwards it to the customer (or their intermediary). If the file is correct, it passes. If not, you get a rejection notice. The problem is the XML format is strict: one wrong tag and the invoice is refused.

What data must an e-invoice for flat-rate taxpayers contain?

An electronic invoice for forfettari follows the same XML schema as a regular invoice, with some differences in the fiscal data. Here are the mandatory elements:

• Seller data: VAT number, name/business name, address, REA (if any).
• Buyer data: VAT number or tax code (codice fiscale) for private individuals. If the buyer is a private person, use their tax code; if they don't provide one, use 00000000000.
• Invoice date and number: unique progressive per year.
• Nature of transaction: since flat-rate taxpayers do not charge VAT, you must use nature N2.2 (operation not subject to VAT due to flat-rate regime). Other natures like N1, N2.1, N3 may apply for exports, etc. Using the wrong nature can lead to rejection or deduction issues for the buyer.
• Amount and taxable base: total amount net of VAT. Withholding tax (ritenuta d'acconto) at 20% must be indicated in the relevant field if you are a professional.
• Recipient code: if the buyer has an SDI code (7 characters) or a PEC, insert it. For private individuals, use 0000000 (seven zeros) plus their tax code.

Here is an example XML snippet for a flat-rate invoice (summary section):

<DatiBeniServizi>
  <DettaglioLinee>
    <NumeroLinea>1</NumeroLinea>
    <Descrizione>Tax consultancy</Descrizione>
    <Quantità>1.00</Quantità>
    <PrezzoUnitario>500.00</PrezzoUnitario>
    <PrezzoTotale>500.00</PrezzoTotale>
    <AliquotaIVA>0.00</AliquotaIVA>
    <Natura>N2.2</Natura>
  </DettaglioLinee>
  <DatiRiepilogo>
    <ImponibileImporto>500.00</ImponibileImporto>
    <AliquotaIVA>0.00</AliquotaIVA>
    <Natura>N2.2</Natura>
  </DatiRiepilogo>
</DatiBeniServizi>

How to send the e-invoice to the SDI system?

You have three practical ways to send your electronic invoices as a flat-rate taxpayer:

1. Free invoicing portal from the Italian Revenue Agency — the "Fatture e Corrispettivi" site (access with SPID/CIE). You can fill and send online. Free but basic: no accounting integration, no deadline tracking.
2. Professional management software — like the one we built at Meteora Web for our clients. Many offer integrated e-invoicing with SDI submission, storage, and reminders.
3. Third-party APIs or services — generate the XML and send via PEC or through intermediaries like Aruba, Infocert, etc.

Our advice: if you issue fewer than 50 invoices a year, the free portal works fine. Above that, a management software saves hours and reduces errors. We come from accounting, so we know: a wrong nature code can cost you a fine.

Sending via PEC

If the buyer has no SDI code, you can send the invoice to a PEC (certified email) of the buyer or their accountant. The PEC must be registered to the correct entity. We automate this check in our tools.

What are the deadlines and penalties for mistakes?

Electronic invoices must be issued within 12 days from the date of the transaction (D.Lgs. 127/2015). In practice: within 12 days you must send the XML file to SDI. The invoice date is up to you, but the sending must happen within that window.

Penalties:

• Missing or late issuance: €250 to €2,000 (reduced if corrected within 30 days).
• Wrong invoice (e.g., wrong nature): €100 to €1,000 per document.
• Missing mandatory digital storage (conservazione sostitutiva): €100 to €1,000.

Forfettari face the same fines as standard regime taxpayers. A client of ours got a €300 fine for forgetting the €2 stamp duty (bollo) on an invoice above €77.47. A small detail that can hurt.

How to manage e-invoices without expensive software?

It depends on your volume. If you are a low-volume forfettario, here is a low-cost strategy:

1. Use the free Revenue Agency portal to fill and send.
2. Download the generated XML and back it up.
3. For digital storage, use the free archiving service included in the portal or a third-party service (stamp duty costs €2 per practice).
4. For withholding tax, calculate 20% on the fee and include it in the XML (Ritenuta field).

If you issue more, consider a proper software. At Meteora Web, we built a management tool for freelancers that integrates e-invoicing, automatic SDI submission, reminders, and CRM. We use it with our clients and know how much it cuts down errors. Because we've seen too many accountants waste time fixing hand-crafted XMLs.

Watch out for subscription-based services

Many online services charge a monthly fee for e-invoicing. If you invoice little, the annual cost may exceed the benefit. Example: €10/month for 20 invoices means €6 per invoice. Not worth it. The free portal does everything, albeit less conveniently.

What to do now

1. Check your current status: if you are a forfettario and haven't switched to e-invoicing yet, start immediately with the Fatture e Corrispettivi portal.
2. Review pending invoices: any paper invoices must be converted to electronic format within 12 days of their date.
3. Decide on your sending method: free portal for low volume, management software for scale.
4. Set a reminder: mark your calendar for invoice issuance and storage deadlines.
5. If in doubt about nature N2.2, consult an accountant. Better to spend on advice than on fines.

For a complete tool that includes e-invoicing, check out our management software for freelancers (Italian).