
Accounting outsourcing legal obligations in Cossonay without the stress: how it works
Whether you run a Sàrl, an SA or a sole proprietorship in Cossonay, accounting outsourcing eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for accounting outsourcing
Swiss accounting law has been unified in the Code of Obligations since 2013: the same bookkeeping rules (art. 957a CO) and retention rules (art. 958f CO — 10 years for books, vouchers and reports) apply regardless of legal form. Accounting outsourcing sits squarely within this frame, including for companies based in Cossonay.
For accounting outsourcing, the classic early mistake remains mixing private and business: a dedicated bank account and documented private withdrawals eliminate half the discussions with the tax office.
Year-end closing: how the mechanics work
The closing is prepared all year long: a monthly bank reconciliation and accruals tracked as you go turn the year-end into a formality, for businesses in Cossonay too.
A clean closing pays beyond the legal duty: it conditions the tax return, bank discussions and the company's value in a succession. Hidden reserves (accelerated depreciation, provisions) remain admissible within cantonal tax limits — document them systematically.
A Swiss SME's accounting calendar
The professionals' trick: handle every deadline at D-30, not D-1. A VAT return prepared a month early leaves time to chase a missing document without penalty.
For accounting outsourcing, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.

Outsource accounting outsourcing 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.
In Cossonay, as everywhere, the right collaboration rhythm follows the activity: monthly for payroll and data entry, quarterly for VAT, yearly for the closing and tax advice.
Cossonay: what changes, what does not
Sole proprietorship, Sàrl or SA in Cossonay: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Vaud.
Federal deadlines do not move in Cossonay: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 1304 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 Cossonay 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 Cossonay: the CO dictates it, not the commune.
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 Cossonay.
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 Cossonay as anywhere.
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