XML Invoice Received by Email — What Now? From panic to paid in three steps

There’s a new email in your inbox. A supplier sent an invoice, but instead of the usual PDF, there’s an XML file attached. You open it and see nothing but code. No amounts, no clear layout — just angle brackets and technical jargon.

Don’t panic. You’re not the only one, and it’s easier to fix than you think.

Why are you suddenly getting XML invoices?

In short: Europe is switching to electronic invoicing. Instead of PDFs that you print or process manually, businesses are now required to send structured e-invoices — XML files that software can read automatically.

This isn’t your supplier’s choice to make your life harder. It’s legislation:

• Belgium — B2B e-invoicing mandatory from January 2026
• Germany — Receiving e-invoices mandatory since January 2025
• France — Mandatory from September 2026
• Poland — KSeF system mandatory from February 2026
• Italy — Already mandatory since 2019

And the list is growing. The EU is making e-invoicing mandatory for all B2B transactions across the EU from 2030 (ViDA regulation).

So that XML attachment in your email? That’s the future of invoicing. And you’re going to receive a lot more of them.

What’s actually in that XML file?

Everything you’d find on a regular invoice — but in a format that computers can read:

• Invoice number and date
• Supplier details (name, address, VAT number)
• Line items (products/services, quantity, price)
• Total amount and VAT
• Payment information (IBAN, due date)

If you open the file in a text editor, you’ll see this:

<cbc:ID>INV-2026-0472</cbc:ID>
<cbc:IssueDate>2026-02-20</cbc:IssueDate>
<cbc:DueDate>2026-03-20</cbc:DueDate>
<cac:AccountingSupplierParty>
  <cac:Party>
    <cbc:Name>Smith & Partners Ltd</cbc:Name>
    ...

All the information is there. The problem is that you can’t read it without the right tool.

How to open an XML invoice from your email

You have three options, from quick to ideal:

Option 1: Upload to a web viewer

Save the attachment and upload the file to an online viewer. You’ll see a readable invoice in your browser.

Downside: You’re sending your invoice data — supplier name, amounts, IBAN — to someone else’s server. Not ideal for confidential business documents.

Option 2: Import into your accounting software

If your accounting software supports UBL or Peppol import, you can import the XML file directly.

Downside: Not every package supports it. And sometimes you just want to look at the invoice — check the amount, verify supplier details — without immediately booking it.

Option 3: Open it with UBL Buddy

UBL Buddy makes opening XML invoices as easy as PDFs. Save the attachment, double-click, and you’ll see a clear invoice.

How it works:

1. Save the XML attachment from your email
2. Open the file with UBL Buddy (or double-click — UBL Buddy automatically becomes your default XML invoice viewer)
3. View the invoice: supplier, amounts, line items, payment information

On iPhone or iPad: Tap the XML attachment in your email → choose “Open in UBL Buddy” → view the invoice directly.

Why this is the best option:

• Works offline — Your invoice data stays on your device. Nothing gets uploaded.
• Instant — No browser, no account, no registration.
• Pay immediately — Scan the QR code or tap to open your banking app with pre-filled payment details (Pro feature).
• Save attachments — If there’s a PDF or Excel file embedded in the e-invoice, you can save it directly (Pro feature).

Free to use for opening and viewing invoices. Pro (€14.99/year) adds payment features and attachments.

Do you need to notify your supplier?

No. An XML invoice is a regular invoice — just in a different format. You don’t need to do anything special except:

1. View it — Check that the details are correct
2. Pay it — Before the due date, just like any other invoice
3. Keep it — For your records (the XML file itself is your invoice)

Your supplier doesn’t expect confirmation that you were able to open the file. Just paying is enough.

What if you can’t open the file?

A few common issues:

“The file opens as text/code”

Your Mac or PC opens XML files in a text editor by default. Install UBL Buddy and set it as the default app for XML invoice files. After that, a double-click will open the invoice directly.

”I see nothing when I open the attachment”

Some email apps show XML files as empty attachments. Save the file to your device first, then open it.

”The file name has .xml but also other extensions”

Sometimes suppliers send invoices with extensions like .ubl, .peppol or .xml. They’re all XML files. UBL Buddy recognizes them automatically.

”My Mac says the file can’t be opened”

Right-click the file → “Open with” → choose UBL Buddy. If you don’t have UBL Buddy yet: download it free from the Mac App Store.

Frequently asked questions

Is it safe to open an XML attachment?

Yes. XML files are plain text data — not executable files. They can’t contain viruses or malware. They’re simply structured invoice data.

Can I convert the XML file to PDF?

You can with some tools, but it’s rarely necessary. The XML file is your invoice — it’s the official document. If you want a readable version, open it with UBL Buddy and take a screenshot or print if needed.

Should I keep both the XML and the PDF?

If your supplier sends both: keep the XML file. That’s the legally valid document in countries with e-invoicing mandates. The PDF is just a visual representation.

I use Windows — what now?

UBL Buddy is currently available for Mac, iPhone and iPad. A Windows version is planned. Until then, you can use web viewers to open the XML file.

Are all my invoices going to come in XML now?

Increasingly, yes. As EU countries mandate e-invoicing, it’s shifting from “occasionally an XML attachment” to “most invoices in XML format.” It’s smart to have a good workflow in place now.