
Withholding tax for agencies in Märstetten: the practical guide
Withholding tax for agencies in Märstetten rests on three pillars: federal law that applies across Switzerland, cantonal deadlines worth knowing, and tools that eliminate re-keying. This guide puts it all in order, fact by fact.
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.
Digitalising withholding tax: what actually works
Artificial intelligence has changed the economics of withholding tax: automatic invoice reading reaches recognition rates that make manual entry marginal, and posting suggestions learn from corrections. The accountant does not disappear — the job shifts from data entry to control and advice.
For withholding tax, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
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 Märstetten. They come on top of the federal social insurances and appear on every payslip.
For withholding tax, the practical challenge is the calendar: AHV instalments during the year, salary declaration to the compensation office in January, salary certificates for staff, and final LPP/accident settlements. A clean payroll base avoids unpleasant catch-up invoices.

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 Märstetten) 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.
Märstetten: what changes, what does not
Märstetten (postal code 8560, canton Thurgau) applies the same federal rules as the rest of the country: what changes in Märstetten are the cantonal counterparts — tax administration, compensation office, commercial register.
Märstetten requires no special bookkeeping: the Code of Obligations applies at postal code 8560 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
Which social contributions does a Swiss employer pay?
AHV/IV/APG: 5.3% employer share (the same is withheld from the employee); unemployment insurance: 1.1% each up to CHF 148,200 a year; occupational pension (LPP) by age and plan (employer at least 50%); occupational accident insurance paid by the employer; family allowances by canton. For an employer in Märstetten, family allowances follow the canton's rates.
Which documents should be prepared for the year-end closing?
Bank and cash statements at the closing date, the inventory of stock and work in progress, final AHV/LPP/accident settlements, contracts signed or amended during the year, invoices straddling two years and the detail of accruals. With an up-to-date document archive, most of it is already there. The list is identical in Märstetten: the CO dictates it, not the commune.
Do you need a fiduciary for withholding tax, or can you do it yourself?
Both are defensible. Below CHF 500,000 of revenue, a sole proprietorship may keep simplified accounts itself. As soon as payroll, VAT and a closing with tax stakes are involved, professional support prevents mistakes that cost more than the fees. With a shared platform, the fiduciary does not even need to be in Märstetten.
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 Märstetten as anywhere.
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Switch to accounting that keeps itself up to date
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