Rounding VAT on Swiss Invoices (MWST-Rundung): What the Law Says and What Is Just Habit

At 8.1%, the VAT on CHF 1,234.50 is CHF 99.9945 — a figure no till, ledger or bank account can hold. Every invoicing tool must decide what to do with it, and the law leaves that to you: neither the Value Added Tax Act (MWSTG) nor the Ordinance (MWSTV) contains a rounding provision.[1][2] What the law fixes instead is what the invoice must show, and what you owe when the printed tax is too high.[1] Here is what applies in practice — and how to keep totals clean.

What Swiss VAT law actually requires

The frame, not the decimals: an invoice must show “the applicable tax rate and the tax amount payable on the consideration”; for tax-inclusive prices, the rate alone suffices.[1]

The anchor is the consideration: the tax is what the applicable rate yields on what you actually charge, so rounding comes last — never inside the calculation.[1]

One provision does bite: show too high a tax and you owe the tax shown, unless the invoice is corrected or the Confederation is shown to have suffered no loss of tax — upward-rounded VAT is real debt, not cosmetics.[1]

The printed figure travels on: a taxable client deducts “the domestic tax invoiced to them” as input tax[1]; a method that changes monthly exports noise into their books too.

Commercial rounding is the working standard

With the statutes silent, practice falls back on kaufmännisches Runden — round to the centime, halves up — the commercial standard the ESTV itself works with.[3]

Its publications touch Rundung only in passing, and commercial rules are what they apply: MWST-Info 09 deems rounding of the computed input-tax correction key by commercial rules (“kaufmännischen Regeln”) to at least two decimal places appropriate.[3]

Software differs on where to round: per line then sum, or sum the net per rate and round once; both are defensible, differing by a centime or two at most.

Where the law does fix arithmetic it fixes consistency, not decimals: a foreign-currency conversion basis — monthly average, daily or group rate — must be kept for at least one tax period; give your rounding method the same stability.[2]

Cash, coins and the five-Rappen habit

The famous five-Rappen rounding is a payment custom with a physical cause: the two-centime coin went out of circulation on 1 January 1978 and the one-centime coin on 1 January 2007, leaving the five-Rappen piece as the smallest Swiss coin.[4]

Till totals are therefore rounded to the nearest five centimes — nobody can pay, or make change, to the centime in coins; the habit governs the cash moment, not the invoice arithmetic.[4]

Electronic payments need no coins: a QR-bill or bank transfer settles the exact centime amount, so nothing forces five-centime steps on invoices paid that way.

If you round a cash total, show both figures — the computed total and a separate “cash payment rounded” line — so the tax stays tied to the consideration and the difference stays bookable.

A practical checklist for clean totals

Foreign-currency invoices convert first and round last: for calculating the VAT payable, a consideration in foreign currency must be converted into Swiss francs at the date the tax claim arises, at the FTA monthly average or daily rate.[2]

Never round the net or massage the rate: apply the applicable rate exactly, group mixed-rate invoices per rate, and round only the resulting tax figure per rate.[1]

Reconcile every period: the VAT invoiced per rate should add up to the tax declared; centime differences from line-level rounding are normal — keep them visible rather than balancing them away.

Then lock the setting, in tool and bookkeeping alike, and re-check it after software updates. facturio computes the tax from the consideration at the statutory rate and applies one consistent rounding rule — clean totals without hand-tuning. Sources: [1] Federal Act on Value Added Tax (MWSTG), fedlex; [2] Value Added Tax Ordinance (MWSTV), fedlex; [3] ESTV, MWST-Info 09 Vorsteuerabzug und Vorsteuerkorrekturen, Ziff. 6.2 Rundung; [4] Swiss National Bank, Merkblatt zum Umtausch ausser Kurs gesetzter Münzen.