
SME tax return required documents in Arni (AG): the practical guide
Whether you run a Sàrl, an SA or a sole proprietorship in Arni (AG), SME tax return 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 SME tax return
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. SME tax return sits squarely within this frame, including for companies based in Arni (AG).
Late books show from the outside: poorly calibrated tax instalments, provisional filings, slow answers to the bank. Staying current is also a matter of image.
Year-end closing: how the mechanics work
The order of operations matters: reconciliations first (bank, cash, receivables, payables), then the closing entries, finally the VAT and AHV consistency checks. Reversing the order means starting over.
The timetable is tight: accounts drawn up and approved by the general meeting within six months of the year-end. For SME tax return, chasing missing documents from January (bank statements, contracts, insurance settlements) avoids the last-minute sprint and auditor reservations.
Outsource SME tax return or keep it in-house?
Outsourcing does not exempt you from understanding: an owner who can read the balance sheet and the income statement challenges the fiduciary better — and pays for advice, not re-keying.
In Arni (AG), 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.

A Swiss SME's accounting calendar
Every deadline has an owner: an obligation “of everyone” is kept by no one. Naming one person per deadline family (VAT, payroll, taxes) closes the gaps.
For SME tax return, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Arni (AG): what changes, what does not
Arni (AG) (postal code 8905, canton Aargau) applies the same federal rules as the rest of the country: what changes in Arni (AG) are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Arni (AG): VAT within 60 days, salary declaration in January, 10-year record retention — postal code 8905 changes nothing about those rules, only the sender's address.
Frequently asked questions
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 Arni (AG) as anywhere.
Does MyFiducia.ai work for a business based in Arni (AG)?
Yes: the platform runs online, the rules applied are federal (VAT, CO, AHV), and the file can be shared with any fiduciary. A business in Arni (AG) manages its documents, VAT and exports exactly as anywhere in Switzerland.
How long must records related to SME tax return 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 Arni (AG) can therefore archive fully digitally.
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 Arni (AG) as anywhere.
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