Formal Notice of Default in Switzerland: Letter Template for an Unpaid Invoice

Your client still hasn't paid after a reminder? Send them a written formal notice of default (mise en demeure / Inverzugsetzung) with a clear final deadline. In Switzerland, this is the formal reminder (Mahnung / interpellation) under Art. 102 of the Code of Obligations (CO; OR in German): it puts your client in default, starts default interest of 5% (Art. 104 CO) and prepares your request for debt enforcement (Betreibungsbegehren / réquisition de poursuite).

Below you'll find a complete Swiss notice of default to copy.

One detail matters before you start. Search online for a template and you'll mostly find foreign ones, for example from France, Belgium or Quebec. They talk about an "injonction de payer" (a court order for payment), a flat €40 recovery fee or a "commissaire de justice" (bailiff). None of this exists in Switzerland.

Take Camille, a freelance graphic designer in Lausanne (a fictional example). She delivered a logo for CHF 2,400.00, her client ignored a friendly reminder, and she's torn between sending a second reminder and calling a lawyer.

She doesn't need either at this stage. A well-written letter, sent by registered mail, is enough to move to the next step. This guide shows you which letter, and what comes after it.

Key points

• A Swiss notice of default is a simple written statement from the creditor demanding payment without further delay (Art. 102 para. 1 CO). No special legal form, no lawyer needed.
• It sets the start date for default interest of 5% a year (Art. 104 CO), if your client isn't already in default. You'll need this date in the request for debt enforcement (Art. 67 para. 1 no. 3 of the Debt Enforcement and Bankruptcy Act, SchKG / LP).
• It isn't required before debt enforcement and doesn't interrupt the limitation period. Only debt enforcement, an application for conciliation, a court action or your client's acknowledgment of the debt does that (Art. 135 CO).
• "30 days net" printed on the invoice isn't always enough: the cantonal courts disagree. When in doubt, send the notice of default.
• Reminder fees are only owed if they were agreed or if they are proven damage. There's no statutory flat fee as in France.

What is a notice of default under Swiss law?

In Switzerland, the notice of default (or formal reminder) is the statement in which the creditor demands that the debtor pay a debt that is due. Under Art. 102 para. 1 CO, it puts the debtor in default. From that moment, default interest of 5% a year runs on the amount owed.

In its 2017 report on debt collection agencies (in French), the Federal Council simply defines this demand for payment as a statement from the creditor to the debtor saying that the creditor requires payment of what is owed without further delay.

What it triggers: default and 5% interest

Default has three concrete effects for you:

• Default interest of 5% a year, even if a lower rate was agreed. A higher rate applies if it's in your contract (Art. 104 CO).
• No fault required: your client owes the interest even if they aren't responsible for the delay, the same report notes.
• Further damage can be claimed if it exceeds the interest and you can prove it (Art. 106 CO). According to the Federal Supreme Court case law cited in the report, it isn't added on top of the interest.

What it doesn't do

A notice of default is not a precondition for debt enforcement (Betreibung / poursuite). The federal SME portal says so clearly: sending a reminder is "not required, but highly recommended" (kmu.admin.ch).

It also doesn't interrupt the limitation period. Many freelancers believe the opposite.

Art. 135 CO only lists your client's acknowledgment of the debt and enforcement or court steps. If your invoice is close to becoming time-barred, a letter won't save it: see our article on limitation periods for invoices.

Do you actually need a notice of default?

Not always. Art. 102 para. 2 CO sets out an exception: if the payment date was fixed by agreement, your client is in default as soon as that day passes. No reminder. No letter.

If no deadline was agreed at all, the debt is due immediately (Art. 75 CO). But due doesn't mean in default: your formal reminder is what makes the difference. Our article on payment terms explains this distinction in detail.

The contested point: "30 days net" on the invoice

Does a deadline printed on your invoice count as a formal reminder? The courts don't all give the same answer.

• One reading says yes. In 2003, the civil chambers of the Aargau High Court (Obergericht) and the Aargau Commercial Court changed their practice: an invoice marked "netto 30 Tage" also counts as a formal reminder that triggers default interest under Art. 102 para. 1 CO (AGVE 2003 No. 6). According to the Vaud Cantonal Court, case law in Valais points the same way.
• Another reading says no. The Vaud Cantonal Court points out that an invoice is in principle only information about the amount owed. Under its case law, "30 days net" doesn't count as a formal reminder unless the creditor expresses their intent more firmly (decision of May 20, 2019). The same decision adds that, without an earlier formal reminder, interest only runs from service of the payment order (Zahlungsbefehl / commandement de payer).

We won't settle this debate here. The practical advice, though, is simple:

1. For your next projects, write a specific due date in the quote, contract or your terms and conditions, and get it accepted.
2. For an invoice that's already overdue, send a notice of default. It only costs the price of a registered letter and sets a clear date, in black and white.

Before you get there, have you already sent a friendly payment reminder? A simple oversight is often resolved at this stage. The notice of default is the formal step after that.

Swiss vs. French notice of default: 5 mistakes in online templates

Picture Marco, a fictional web developer in Geneva. He copies a French template he found online, with "indemnité forfaitaire de 40 €" (a flat €40 recovery fee) and "à défaut, je saisirai le juge par voie d'injonction de payer" (otherwise I will apply to the court for an order for payment). Two days later, the client's fiduciary replies that these rules don't exist in Switzerland.

The client disputes the fees, and Marco loses time and a bit of credibility. His second letter, this time a Swiss one, is paid within ten days.

Here are the five mistakes to remove from any foreign template:

1. "Injonction de payer" (court order for payment): in Switzerland, the next step is the request for debt enforcement at the debt enforcement office (Betreibungsamt / office des poursuites). No judge examines the claim at this stage: according to the canton of Geneva, the office has neither the competence nor the duty to check whether the claim is justified (ge.ch, in French).
2. "Indemnité forfaitaire de 40 €" (flat €40 fee): a French rule, between businesses. In Switzerland, fees are only owed if they were agreed, or as proven damage (Art. 106 CO). Under the prevailing legal doctrine, the cost of the first reminder is in principle not recoverable, because your client isn't yet in default.
3. "A notice of default is mandatory before any proceedings": not in Switzerland, you can start debt enforcement without one.
4. "A notice of default interrupts the limitation period": no, see Art. 135 CO.
5. Articles of the French or Quebec Civil Code: cite the Swiss Code of Obligations, Art. 102 to 104 CO. An attentive client will notice the difference.

What a Swiss notice of default must contain

The law doesn't prescribe any particular form for the formal reminder. A clear, dated letter, sent in a way you can prove, does the job. Here's the checklist:

• Your details and your client's (sole proprietorship name, address, UID or VAT number if you have one).
• The basis of the claim: accepted quote, contract, order, with the date.
• The invoice concerned: number, date, amount in CHF.
• Previous reminders, with their dates.
• An explicit demand for payment: "I hereby formally give you notice of default and demand payment of…".
• A specific final deadline, as a date. In practice, 10 to 14 days. No statutory provision sets this figure.
• Default interest of 5% and its start date.
• Reminder fees, only if they're in your terms and conditions or contract.
• Notice that you'll file a request for debt enforcement if the deadline isn't met.
• Your payment details, ideally with the QR-bill.
• Date and signature.

Don't add: made-up fees, interest on default interest (ruled out by Art. 105 para. 3 CO) or threats of a criminal complaint. These additions weaken your letter instead of strengthening it.

Notice of default letter template (Switzerland) to copy

Copy this template, replace the brackets and delete the options that don't apply to you. Write amounts in Swiss format (CHF 2'400.00) and dates as dd.mm.yyyy.

Debt enforcement offices and courts work in the canton's official language (German, French or Italian), so sending the letter in that language avoids a request for translation.

[First name Last name / Sole proprietorship]
[Address] · [Postcode Town]
[UID / VAT no. if applicable] · [email] · [phone]

REGISTERED MAIL (copy by email to [client's email address])

[Client: company or name]
[Address]
[Postcode Town]

[Place], [dd.mm.yyyy]

Formal notice of default – invoice no. [number] of [dd.mm.yyyy]

Dear Sir or Madam,

By [quote accepted on dd.mm.yyyy / contract of dd.mm.yyyy / order of dd.mm.yyyy],
you instructed me to provide [description of the service]. I performed this
service and sent you invoice no. [number] of [dd.mm.yyyy] for
CHF [amount], payable [by dd.mm.yyyy at the latest / within [number] days].

Despite [my reminder of dd.mm.yyyy / my reminders of dd.mm.yyyy and dd.mm.yyyy],
this amount remains unpaid to date.

I hereby formally give you notice of default and demand payment of
CHF [amount] by [dd.mm.yyyy] at the latest.

In accordance with Art. 104 CO, default interest of 5% a year will be due
from [dd.mm.yyyy: the day after the above deadline].

[Variant if a specific due date had been agreed:
Payment was agreed for [dd.mm.yyyy] at the latest. You have therefore
been in default since [dd.mm.yyyy] (Art. 102 para. 2 CO), and default
interest of 5% a year has been running since that date (Art. 104 CO).]

[Optional, only if provided for in your terms and conditions or contract:
Reminder fees of CHF [amount] are due under section [number]
of my terms and conditions.]

Payment can be made using the enclosed QR-bill
(IBAN [CH..], reference [reference]).

If full payment is not received by this deadline, I will file a request
for debt enforcement with the competent debt enforcement office without
further notice. If you dispute this invoice, please let me know
in writing before that date.

Yours faithfully,

[Signature]
[First name Last name]

Enclosures: invoice no. [number], reminder of [dd.mm.yyyy] (with QR-bill)

Why interest from the day after the deadline, and not from receipt? It's the cautious choice. You claim a few francs less, but your start date is hard to dispute. If a specific due date had been accepted, use the variant in the template instead.

How to send your notice of default (and keep the proof)

Registered mail plus a copy by email

Registered mail isn't mandatory, but it's your proof. The letter is only handed over against a signature (or to an authorized person), and Swiss Post's online tracking documents posting and delivery. Tracking says nothing about what was in the envelope, though. So keep a signed copy of your letter and send the same PDF by email on the same day.

As for cost, a domestic registered letter (up to B4) costs CHF 5.80 if it's already franked and ready to send, or CHF 6.80 if the branch franks it at the counter, according to Swiss Post's prices checked in November 2026.

Attach the reminder with the QR-bill and keep the send history

This is where your invoicing software saves you time. Before writing the letter, create a reminder from the unpaid invoice in Magic Heidi. You get the same invoice as a PDF, marked as a reminder and with a short sentence asking for prompt payment.

If your IBAN is saved, this PDF keeps the QR-bill. Your client can pay by scanning the code, without typing in an IBAN. Attach it to your notice of default.

You can then send it by email from the app, with an editable subject and message. If you prefer paper, Magic Heidi can also print and post a letter by B Mail, which arrives in about 3 working days. Note: B Mail isn't registered mail. If you want the proof that registered mail gives you, send your notice of default yourself, from the post office.

The most useful part comes afterwards. Every send is logged on the invoice: date, document type (invoice or reminder), recipient and delivery status. When you fill in the request for debt enforcement, you have the dates of your sends at hand.

Want to see what this history looks like? Try the Magic Heidi invoicing software on your next invoice: the free version lets you create 3 invoices, no credit card needed.

How long should you wait?

The law sets no deadline for a notice of default. You choose the date you write in the letter. In practice, 10 to 14 days after receipt gives your client time to pay without letting the matter drag on.

Put the date in your calendar. If it passes without payment, act: a threat of debt enforcement that goes nowhere loses its effect next time.

Calculating 5% default interest: an example

Back to Camille. She sends her notice of default on November 1, 2026, with a deadline of November 15, 2026. Interest therefore runs from November 16, 2026. The client finally pays on January 31, 2027. From November 16, 2026 to January 31, 2027 inclusive, that's 77 days of interest.

CHF 2,400.00 × 5% × 77 / 365 = about CHF 25.32

The amount is modest, but it adds up when the delay drags on or the invoice is large. Day-count conventions vary: without counting the payment day, or on a 360-day basis, you get about CHF 25.00. For the details, see how to calculate default interest. A useful reminder: no interest on default interest (Art. 105 para. 3 CO).

Your client still hasn't paid: the request for debt enforcement

Has the deadline in your notice of default passed? The next step is the request for debt enforcement, filed with the debt enforcement office where your client lives or has its registered office. You can file it online via EasyGov.

1. Fill in the request: creditor, debtor, amount in CHF and, for an interest-bearing claim, "the interest rate and the date from which the interest is demanded" (Art. 67 para. 1 SchKG). This is where the date from your notice of default comes in.
2. Advance the costs: they're borne by the debtor, but you advance them (Art. 68 SchKG). The fee for the payment order is set by the federal government according to the amount: CHF 60 for a claim of more than CHF 1,000 up to CHF 10,000, like Camille's, plus CHF 7 per attempt at service (Art. 16 of the Fee Ordinance, GebV SchKG / OELP). The federal SME portal puts the costs at between CHF 50 and CHF 100 for a claim of less than CHF 10,000.
3. The office serves the payment order: your client has 20 days to pay and 10 days to file an objection (Rechtsvorschlag / opposition) (Art. 69 and 74 SchKG).
4. If your client objects, you need a court to set the objection aside, through a court action or through the procedure to set aside the objection (Rechtsöffnung / mainlevée) (Art. 79 to 82 SchKG). If there's no objection, you can request continuation of the debt enforcement after 20 days, and no later than one year after service (Art. 88 SchKG).

The whole procedure, forms included, is explained in our guide to starting debt enforcement in Switzerland.

If your client replies and acknowledges the debt

A notice of default often gets a reaction. Take Sophie, a fictional translator in Fribourg. Her client writes: "I know I owe you the CHF 3,600.00, but I can't pay it all this month."

Don't settle for that email. Have your client sign an acknowledgment of debt (Schuldanerkennung / reconnaissance de dette) stating the amount and the payment dates.

Once signed, it lets you request provisional setting aside of the objection (provisorische Rechtsöffnung / mainlevée provisoire) if your client ever objects (Art. 82 SchKG). It also interrupts the limitation period (Art. 135 CO). Sophie adds a plan with three instalments and recovers the full amount within three months.

Ongoing project? Set a deadline before you continue

If you're still working for this client, the Code of Obligations gives you some room. In a bilateral contract, you can set an appropriate deadline. If it passes without payment, you can, among other things, withdraw from the contract or claim damages, provided you declare this immediately (Art. 107 CO). In complicated cases, get advice before terminating.

And going forward, a prevention tip: if you invoice this client every month, let Magic Heidi send the recurring invoice automatically (monthly, quarterly or yearly). It goes out on a fixed date, without you having to think about it.

Conclusion: one letter, one date, then debt enforcement

A notice of default in Switzerland needs neither a lawyer nor a magic formula. Remember three points:

• It sets the start date for 5% interest, which you'll need for the request for debt enforcement.
• It isn't required before debt enforcement and doesn't interrupt the limitation period.
• A deadline only printed on the invoice is contested: agree on a specific date in the quote, otherwise send the letter.

Your next step: copy the template, set a date and send it by registered mail with a copy by email. If the date passes, file the request for debt enforcement.

General information, not legal advice. For a large amount or a disputed claim, consult a lawyer or a legal advice service. Sources: CO, SchKG and GebV SchKG on fedlex.admin.ch, Federal Council report of March 22, 2017, AGVE 2003 No. 6, decision of the Vaud Cantonal Court of May 20, 2019, kmu.admin.ch, ge.ch, Swiss Post. Updated: November 2026.