Advance Invoice in Switzerland: Which Fields Are Legally Required

An advance invoice is not a standard invoice — and that's precisely where many businesses stumble. Many Swiss SMEs and freelancers simply use their standard invoice template, change the amount, and send it off. The problems only surface when the customer refuses payment, the accountant asks questions, or the tax authority challenges your VAT return. This article explains which fields must be included on an advance invoice — and what typically gets overlooked.

How an advance invoice differs from a standard invoice

Formally, an advance invoice is a bill for a partial payment issued before or during service delivery. It creates a claim without the complete service being finished yet. This has consequences for how you structure the document:

• The term "advance invoice" or "deposit invoice" must appear clearly in the document title. Simply writing "Invoice No. 2026-041" without further clarification creates confusion — for the customer, for both parties' accounting, and for VAT reporting.
• The link to the overall contract should be evident: either through an order number, project name, or explicit wording like "Advance payment according to quote No. 2026-007 dated 15 August 2026".
• The remaining balance is not legally mandatory, but it significantly increases transparency. Most customers appreciate seeing immediately how much remains unpaid after the deposit.

Mandatory fields overview

The Swiss invoice template with all required fields serves as the foundation — an advance invoice requires several additional or modified fields beyond this.

Base information (identical to every invoice)

Field	Note
Invoicing party name and address	incl. VAT ID if VAT-registered
Invoice recipient name and address	exactly as per order
Invoice date	date of issue
Unique invoice number	from continuous numbering
Payment term / due date	e.g. "Due by 30 September 2026"
IBAN or QR-IBAN	for bank transfer or QR-bill payment

Fields specific to advance invoices

1. Clear designation as an advance invoice Write prominently and clearly: "Advance Invoice" or "Deposit Invoice". Some accountants also recommend "Partial Invoice 1 of 3" for multi-stage projects — this immediately clarifies which billing stage you're in.

2. Description of the overall service Not just "advance payment", but for what: "Advance payment for web project XY, total contract CHF 12,000.00 excl. VAT". Without this reference, the recipient cannot book the document correctly.

3. Amount of the advance and basis Specify whether the advance equals a fixed amount or a percentage. "30% of contract value, CHF 3,600.00 excl. VAT" is clearer than just "CHF 3,600.00".

4. VAT details — a common mistake If you're VAT-registered, your advance invoice must show the same VAT information as any other invoice: the applicable tax rate (8.1%, 2.6%, or 3.8%), the net amount, VAT amount, and gross amount. VAT arises at the time of invoicing (under the invoice method) or payment receipt (under the cash method). Missing these details jeopardizes the recipient's input tax deduction.

5. Note on the final invoice A single sentence is enough: "This amount will be credited against the final invoice." This makes clear to both parties that the advance model applies and no separate service is being charged.

What to consider with numbering

The advance invoice number must fit into your overall invoice numbering sequence — it cannot leave a gap. For example, if you issue two advance invoices for the same project, each receives its own consecutive number (e.g. 2026-041 and 2026-055). The final invoice also receives its own number and references the prior advance invoices.

A common error: advance invoices get a suffix ("Invoice 2026-041a") that your accounting system doesn't support. This complicates assignment and can raise questions during an audit.

QR-bill: Special considerations for advance invoices

If you use the Swiss QR-bill, explicitly note in the additional field (message field) which contract this relates to and that it's a deposit payment. The QR code contains the exact payment amount — this must match the gross amount shown on your advance invoice.

The guide Create a Swiss QR-bill — step-by-step explains how to set up the payment slip correctly, including proper completion of reference number and message field.

Common errors at a glance

• No "advance invoice" title: The document gets booked as a regular invoice on both sides.
• Missing contract reference: The final invoice cannot later be cleanly linked to the deposit.
• Missing or incorrect VAT: Jeopardizes the recipient's input tax deduction and creates discrepancies in VAT reporting.
• No note about crediting: Customers may pay twice or later dispute the debt.
• Wrong numbering: Gaps or duplicates in invoice numbers complicate audits.

If you want to get started right away, you can create an advance invoice with the SnapBill app, which structures all required fields and automatically generates the QR-bill payment slip.

In brief

A correctly prepared advance invoice contains all standard mandatory fields of a Swiss invoice, plus four additional elements: clear designation as an advance invoice, reference to the overall contract, VAT breakdown on the partial amount, and a note that the amount will be credited to the final invoice. The invoice number belongs in your continuous numbering sequence. By consistently implementing these points, you avoid booking errors on both sides and keep your VAT reporting clean.