
Withholding tax for architecture firms in Bachs: rules, deadlines, best practice
Swiss accounting law (art. 957 ff. of the Code of Obligations) sets a precise frame, yet day-to-day practice often stays fuzzy. This guide walks through what actually matters for a business based in Bachs.
The Swiss legal frame for withholding tax
Three documents summarise the health of a Swiss business: the balance sheet (what it owns), the income statement (what it earns) and the notes (what else you should know). All the work of withholding tax converges on those three pages, in Bachs too.
One simple principle drives withholding tax: every franc in or out must be explainable by a document, an entry and an account. All of Swiss accounting law fits inside that traceability requirement.
Digitalising withholding tax: what actually works
Digitising does not mean hoarding PDFs: without the document-entry link, a digital file is as opaque as a box of archives — true in Bachs as everywhere.
An SME in Bachs that digitalises gains owner time first: less filing, fewer “where is that receipt?” questions, more attention to the trade — that is the real return of withholding tax.
Salaries and social contributions: the rates to know
The salary certificate is an official tax document: it feeds the employee's tax return and serves as the reference in AHV and tax audits. Issued once a year, it must match payroll accounting and the declaration to the compensation office to the centime.
For withholding tax, the gap between agreed gross and paid net surprises every new employer: simulate it BEFORE hiring to avoid misunderstandings with the future employee.

A Swiss SME's accounting calendar
Three families of deadlines shape the year: federal (VAT within 60 days, salary declaration in January), cantonal (tax return, extensions depending on the canton, including in Bachs) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
For withholding tax, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Bachs: what changes, what does not
Working with a fiduciary from Bachs no longer depends on geography: the documents of a business in Bachs are shared online, while the canton Zurich keeps its own deadlines for the tax return.
For a business in Bachs, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Zurich.
Frequently asked questions
What are the current Swiss VAT rates?
Since 1 January 2024: 8.1% (standard), 2.6% (reduced — for example food and medicines) and 3.8% (accommodation). Returns must be filed and paid within 60 days after the period ends (quarterly under the effective method, semi-annually under the net tax rate method). These federal rates apply unchanged in Bachs.
What is simplified bookkeeping and who can use it?
Sole proprietorships and partnerships under CHF 500,000 of revenue may limit themselves to recording income, expenses and assets (art. 957 para. 2 CO). Once over the threshold — or upon founding a Sàrl or an SA — full accounts with balance sheet, income statement and notes become mandatory. The CHF 500,000 threshold is assessed the same way in Bachs.
Effective VAT method or net tax rate: how to choose?
The effective method deducts actual input VAT and files quarterly; the net tax rate method applies a flat industry rate to turnover, semi-annually, with no separate input VAT deduction. The flat rate suits low-cost structures; as investments grow, the effective method usually wins again. The choice rests on the company's own figures, in Bachs as anywhere.
How long must records related to withholding tax be kept?
Ten years from the end of the financial year concerned (art. 958f CO). Electronic retention is permitted if the integrity and readability of the records are guaranteed — a serious digital archive validly replaces paper binders. A business in Bachs can therefore archive fully digitally.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates withholding tax for businesses in Bachs: AI-read documents, posting suggestions, VAT and exports ready for your fiduciary. Try the platform or browse our other guides.
The application is operated in French.