Advance Invoices as a Freelancer: How to Do It Correctly

Large projects often mean a long wait for the full amount — unless you agree on partial payments. The advance invoice is the right tool for this. Yet many freelancers issue them incorrectly: missing VAT declarations, no clear link to the final invoice, or amounts are double-booked at the end. This article shows you how to set up advance invoices correctly — from the first partial invoice to the final overall settlement.

What is an advance invoice anyway?

An advance invoice (also called: partial invoice or progress billing) requests part of the total fee before the service is fully delivered. It's not a discount, not a prepayment without consideration, and not a deposit in the tax sense — but a binding invoice for a defined service portion or an agreed percentage of the total contract.

Typical use cases:

• Web development or software projects with multiple milestones
• Consulting mandates spanning several months
• Graphic design projects with concept, draft and implementation phases
• Construction supervision, architecture or technical planning

Two variants: Performance-based or percentage-based

Variant 1: Performance-based partial invoice

Here you invoice concrete, completed services. Example: You've completed the concept phase in a web project and bill CHF 3,000 for it. This variant is the cleanest from a bookkeeping perspective because the scope is unambiguous.

Variant 2: Percentage-based advance agreement

Often it's agreed that 30% is due upon order placement, 40% at project mid-point, and 30% upon completion. In this case, you issue an advance invoice for the corresponding percentage of the total fee — even if the service hasn't been fully delivered yet.

Important: In both cases, the invoice must contain all required information — including invoice number, date, your UID (if VAT-liable), description of the (partial) service, and VAT declaration. A complete overview of mandatory fields can be found in the practical guide for freelance invoicing in Switzerland.

VAT on advance invoices: What applies?

If you're VAT-liable (turnover over CHF 100,000 per year), you must declare the tax correctly on the advance invoice — not just on the final invoice. The standard rate remains 8.1% in 2026 on most services. Certain industries have the special rate of 3.8% (accommodation) or the reduced rate of 2.6% (e.g. foodstuffs).

Example: Total fee CHF 10,000 excl. VAT, first advance invoice for 30%:

• Service portion: CHF 3,000.00
• VAT 8.1%: CHF 243.00
• Total due: CHF 3,243.00

On the final invoice, you then show the total amount and explicitly deduct all advance invoices already paid, including their VAT amounts. This prevents double-booking with the customer and avoids problems with your own VAT settlement. Learn more about current rates and duties in the overview of Swiss VAT basics 2026.

The final invoice: How to close the loop

The final invoice summarises the entire project. It contains:

Item	Amount
Total fee excl. VAT	CHF 10,000.00
VAT 8.1%	CHF 810.00
Grand total	CHF 10,810.00
Less advance invoice No. 2026-047	– CHF 3,243.00
Less advance invoice No. 2026-061	– CHF 4,324.00
Still outstanding	CHF 3,243.00

Always reference the numbers of preceding advance invoices in the final invoice. This makes it easier for the customer to allocate payments and for your accountant to keep records.

Numbering and sequence

Advance invoices need their own sequential invoice numbers — they must not carry the same number as the final invoice. Many freelancers use a schema like:

• 2026-047 → Advance invoice 1
• 2026-061 → Advance invoice 2
• 2026-078 → Final invoice (with reference to 047 and 061)

The numbers must be consecutive and chronological. Correcting an invoice after it's been sent is possible but complex — Switzerland has no simple "delete" function; instead you issue a credit note and a new invoice.

QR-bill on advance invoices

Since the replacement of the payment slip, the QR-bill is now standard for advance invoices too. Important: The amount embedded in the QR code must exactly match the due partial amount — that is, the advance invoice total including VAT, not the total project value. If you work with a QR-IBAN, you can add a project-related reference number in the reference field to make payment allocation easier for both sides. For step-by-step instructions on building a correct QR-bill, see the Swiss QR-bill creation guide.

For technically creating the invoice with the correct QR code and VAT declaration, SnapBill is ideal — you can create advance invoices with project reference and sequential numbering directly in the app.

Avoid common mistakes

• No reference to the overall project: Always describe which contract the advance invoice belongs to.
• VAT forgotten or miscalculated: The tax amount must be declared separately on every partial invoice.
• Final invoice without deducting advance invoices: This leads to overpayment or confusion on the customer's side.
• Same invoice number for advance and final invoice: Every invoice needs its own, unique number.
• No written payment plan: Without clear contractual basis, it's harder to enforce advance payment if the customer refuses.

At a glance

• Advance invoices are full invoices with their own number, service description and VAT declaration.
• The final invoice shows the grand total and explicitly deducts all advance invoices with their numbers.
• The QR code always contains only the currently due partial amount.
• Without written agreement of the payment plan, the contractual foundation is missing — record the terms in the contract or by email.
• Correct numbering and documentation ease bookkeeping for you and your accountant, and simplify any debt collection if payment is delayed.