Key points at a glance
- An invoice sent as a PDF by email is valid in Switzerland - for VAT (MWST) purposes too. An electronic signature hasn't been required since 2018.
- Send from your own mailbox using your own domain - not from a "noreply" address. That way, questions come back to you.
- Keep a record of which invoice went to whom and when. In a dispute, you have to prove that it was delivered.
- Keep every invoice you send for 10 years, unchanged, as required by the Swiss Code of Obligations (CO) (Art. 958f CO).
Is an invoice sent by email valid?
Yes. The Code of Obligations doesn't prescribe any particular form for an invoice - a PDF attachment is just as valid as a letter. For VAT, too, electronic invoices are treated the same as paper invoices: the former Ordinance on Electronic Data and Information (ElDI-V), which required a signature on electronic invoices, was repealed on January 1, 2018; since then, the principle of free choice of evidence has applied without restriction (Art. 81 para. 3 of the Value Added Tax Act, VATA). What matters is that the invoice contains the mandatory information (Art. 26 VATA) and that you keep it unchanged.
For your customers' input tax deduction, the free choice of evidence applies (Art. 81 para. 3 VATA): the invoice can be backed up by other documents such as the quote, delivery note and payment. A properly structured PDF invoice from software that can't be changed afterward is the best basis for this.
What to include in the email
- A subject line with the invoice number and your business name, for example "Invoice 2026-041 - Muster Elektro".
- A short message with a personal greeting, the amount and the due date - the details are in the PDF.
- The invoice as a PDF with the QR-bill payment part. Many people pay straight from the screen by scanning the QR code with their banking app. How the payment part is structured is covered in the article Creating a QR-bill.
- No Word or Excel files - they can be edited and look unprofessional.
Your own sender address and deliverability
Invoices from a free email address or from "noreply@…" end up in spam more often and look less trustworthy. A mailbox on your own domain is better, for example accounting@yourcompany.ch. For other mail servers to recognize your emails as genuine, three records for your domain need to be set up correctly:
- SPF specifies which servers may send email on behalf of your domain.
- DKIM signs every email so that nothing can be altered in transit.
- DMARC tells recipients what to do with emails that fail SPF or DKIM.
With Microsoft 365 and most Swiss hosting providers, you set this up with a few DNS records; your provider or IT support can help.
Example: the invoice that supposedly never arrived
After the second reminder, a customer of Marco, an electrician, gets in touch: he says he never received the invoice. Marco checks the email history and sees the date, time, recipient address and the status "Sent". He sends the invoice again, along with these details. The customer finds it in his spam folder and pays the same day. Afterward, Marco sets up DKIM for his domain.
Delivery and proof
If you rely on an invoice, you have to prove in a dispute that it arrived (Art. 8 of the Civil Code, CC). A read receipt doesn't help much, because many recipients decline to send one. A complete history is more important: when you sent which invoice to which address - ideally including the original message. You should notice bounce messages from the mail server such as "undeliverable" right away, not only when it's time to send a reminder.
Data protection when sending
Invoices contain personal data, sometimes sensitive data - for example, for therapy or counseling services. Make sure the invoice goes to the right address, especially for customers with several contact persons. A misaddressed invoice is a data security breach; if it poses a high risk to the person concerned, you must report it to the Federal Data Protection and Information Commissioner FDPIC (EDÖB) via the DataBreach reporting portal (Art. 24 of the Federal Act on Data Protection, FADP). More on this in the article Data protection for small firms.
What about eBill?
eBill is the Swiss banks' e-invoicing portal: the invoice appears directly in the customer's e-banking. As an invoice issuer, you need your own access via your bank or a service provider. For most sole proprietorships and small SMEs, a PDF invoice with a QR code is enough - it can be scanned in any banking app. Easly doesn't offer eBill.
How it works in Easly
In Easly, you send quotes, invoices and reminders with one click - from your own mailbox and with a complete history:
- Your mailbox, your sender address: Easly sends via Microsoft 365 or any mailbox with SMTP, for example at Infomaniak, Hostpoint or Gmail. Your customers' replies come straight to you.
- Templates with placeholders: For each document type - quote, order confirmation, delivery note, invoice, dunning notice - you define the subject and text. Easly fills in placeholders such as customer name, document number, amount or due date when sending. You can also store separate templates for individual customers.
- PDF with QR-bill payment part attached: The invoice is attached as a PDF automatically.
- Proofreading: With your own AI access, Easly corrects the spelling and grammar of your templates and emails - leaving the placeholders unchanged.
- Email history: Every email sent, with time, recipient and status. You can open the original message as a preview and download it as an .eml file - your proof if an invoice "never arrived".
- Failed emails appear on the dashboard so you notice them right away.
Frequently asked questions
Is an invoice sent by email legally valid?
Yes. The Code of Obligations doesn't prescribe any form, and for VAT, electronic invoices are treated the same as paper invoices. An electronic signature hasn't been required since 2018. What matters is the mandatory information (Art. 26 VATA) and keeping the invoice unchanged for 10 years.
Do I have to print out an invoice I sent by email?
No. You may keep it electronically as long as it remains complete, unchanged and readable at all times (Art. 958f CO and the Accounting Records Ordinance). A printout isn't necessary.
How do I prove that an invoice arrived?
With email, there's no absolute proof. What helps is a sending log with date, time and recipient address, the original message and the absence of a non-delivery report. For large amounts, you can also send the reminder by registered mail.
Can I send invoices via eBill with Easly?
No. Easly sends invoices by email as a PDF with a QR-bill payment part. Your customers can scan the QR code in any Swiss banking app.
Information as of: see above. Sources: Swiss Code of Obligations (Art. 958f CO), Accounting Records Ordinance (GeBüV, in German), Value Added Tax Act (Art. 26 and 81 VATA), Civil Code (Art. 8 CC), Federal Act on Data Protection (Art. 24 FADP). This article is not a substitute for legal or tax advice.