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Withholding tax alternatives in Solothurn: rules, deadlines, best practice

Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on withholding tax in Solothurn: what the law requires, what can be automated, and when to delegate.

The Swiss legal frame for withholding tax

In Switzerland, the duty to keep accounts stems from art. 957 ff. of the Code of Obligations. Legal entities (Sàrl, SA) and sole proprietorships with at least CHF 500,000 in revenue keep full accounts: balance sheet, income statement and notes. Below that threshold, a simplified record of income, expenses and assets is sufficient.

Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For withholding tax, that means in practice: no movement without a receipt, and an audit trail that can be reconstructed at any time — including during a VAT or AHV inspection.

Salaries and social contributions: the rates to know

Family allowances are financed by the employer through a cantonal compensation fund — rates and amounts vary from canton to canton, including in Solothurn. They come on top of the federal social insurances and appear on every payslip.

A thirteenth salary, where agreed, is accrued month by month — forget it and December reveals a charge of one-twelfth of the payroll, in Solothurn as everywhere.

A Swiss SME's accounting calendar

Extensions exist and can be requested: cantonal deadlines for the tax return, deferral of the VAT filing on a reasoned request. But an extension does not stop interest: on VAT, default interest runs from the ordinary due date even when more time has been granted.

An SME in Solothurn that holds its calendar twelve months straight changes its position: fewer official reminders, easier extensions — and withholding tax stops being a source of worry.

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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 Solothurn as everywhere.

Migrate in stages: supplier invoices first (high volume, immediate gain), then receivables with the QR-bill, finally payroll and the closing. At each stage, comparing one month before/after is enough to prove the gain — no theoretical promises needed.

Solothurn: what changes, what does not

Solothurn (postal code 4500, canton Solothurn) applies the same federal rules as the rest of the country: what changes in Solothurn are the cantonal counterparts — tax administration, compensation office, commercial register.

Solothurn requires no special bookkeeping: the Code of Obligations applies at postal code 4500 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.

Frequently asked questions

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 Solothurn as anywhere.

What is the difference between a limited and an ordinary audit?

The ordinary audit applies to companies exceeding, for two consecutive years, two of three thresholds: CHF 20 million balance sheet total, CHF 40 million revenue, 250 full-time positions. Others fall under the limited audit, and those with no more than ten full-time positions on annual average can opt out with all shareholders' consent. These federal thresholds do not depend on the registered seat — in Solothurn as anywhere.

What are the legal obligations for withholding tax in Switzerland?

The foundation is the Code of Obligations: proper bookkeeping (art. 957a CO), annual accounts (balance sheet, income statement, notes) and 10-year retention of books and records (art. 958f CO). VAT applies from CHF 100,000 of turnover, and social insurance settlements from the first employee. Nothing is different in Solothurn: federal law applies.

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 Solothurn can therefore archive fully digitally.

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Switch to accounting that keeps itself up to date

MyFiducia.ai automates withholding tax for businesses in Solothurn: 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.