
Social security contributions for SA companies in Rheinfelden: 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 social security contributions in Rheinfelden: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for social security contributions
A small business does not mean small obligations: from the first salary or the first VAT return, mistakes get expensive — in Rheinfelden as anywhere.
Also worth knowing: accounts may be drawn up in the currency most relevant to the business; if that is not the franc, values must additionally be stated in CHF (art. 958d para. 3 CO). Internationally active companies gain books that match their economic reality.
Salaries and social contributions: the rates to know
Two of these contributions are set by law: AHV/IV/APG at 5.3% and unemployment at 1.1%, both payable by the employer. The others — LPP, accident insurance, possibly daily sickness benefits and family allowances — depend on the insurer, the industry and the pension plan. The total surcharge usually falls between 12 and 20% of gross pay, and employee deductions between 10 and 15%: these are orders of magnitude, not statutory rates.
For social security contributions, the winning mechanics are simple: one single payroll database (salaries, rates, allowances), monthly slips generated from it, and an annual declaration that is little more than a sum. Painful catch-up invoices almost always stem from scattered data.
A Swiss SME's accounting calendar
January: salary declaration to the compensation office and salary certificates. End of February, May, August, November: quarterly VAT returns (effective method), each to be filed and paid within 60 days after the quarter ends. Within six months of year-end: approved annual accounts. Then: the tax return under cantonal deadlines, with extensions possible.
For social security contributions, deadline discipline is worth real money: default interest on late VAT, AHV adjustments, tax fines. A shared deadline calendar — fed by up-to-date figures — remains the simplest safeguard.

Outsource social security contributions or keep it in-house?
Responsibility stays with the client: the fiduciary executes with care, but the signed accounts bind the company. Understanding what you sign is not optional.
For social security contributions, a quarterly 30-minute check-in with the fiduciary beats an annual marathon: questions get handled while they are small.
Rheinfelden: what changes, what does not
Rheinfelden (postal code 4310, canton Aargau) applies the same federal rules as the rest of the country: what changes in Rheinfelden are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Rheinfelden: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 4310 changes nothing about those rules, only the sender's address.
Frequently asked questions
When must a business register for VAT?
As soon as its worldwide annual turnover reaches CHF 100,000 (CHF 250,000 for non-profit sports or cultural associations). Below that, voluntary registration remains possible and often makes sense to reclaim input VAT on investments. The threshold is federal: it applies in Rheinfelden as everywhere in Switzerland.
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 Rheinfelden: the CO dictates it, not the commune.
When is entry in the commercial register mandatory?
A Sàrl and an SA only come into existence with their registration. A sole proprietorship must register from CHF 100,000 of annual revenue; below that, registration stays voluntary but adds credibility and protects the business name. Registration goes through the canton's commercial register office — for Rheinfelden too.
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 Rheinfelden as anywhere.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Rheinfelden: 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.