
VAT return required documents in Lengnau (AG): the practical guide
VAT return required documents in Lengnau (AG) raises the same questions for most Swiss SME owners: which obligations apply, which deadlines are running, which documents to prepare. This page covers the federal rules in force — without unnecessary jargon.
The Swiss legal frame for VAT return
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.
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.
Digitalising VAT return: 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 Lengnau (AG) as everywhere.
For VAT return, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
Outsource VAT return or keep it in-house?
A good test before choosing: ask the fiduciary HOW it wants to receive the documents. A precise answer (formats, frequency, platform) says more than any brochure — including in Lengnau (AG).
For VAT return, a quarterly 30-minute check-in with the fiduciary beats an annual marathon: questions get handled while they are small.

Swiss VAT: rates, threshold and filings
Registration happens with the Federal Tax Administration and yields a VAT number based on the business identifier (format CHE-xxx.xxx.xxx VAT). From then on, every invoice must state that number, the rate applied and the tax amount — three details VAT return should lock down from day one to avoid retroactive fixes.
For an SME in Lengnau (AG), electronic filing of VAT returns has been mandatory since 1 January 2025; the tax administration's online portal is also where extensions are requested and past periods consulted. Combined with accounts that prepare the return automatically, VAT return stops being a quarterly chore.
Lengnau (AG): what changes, what does not
Sole proprietorship, Sàrl or SA in Lengnau (AG): the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Aargau.
Lengnau (AG) requires no special bookkeeping: the Code of Obligations applies at postal code 5426 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
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 Lengnau (AG).
Does MyFiducia.ai work for a business based in Lengnau (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 Lengnau (AG) manages its documents, VAT and exports exactly as anywhere in Switzerland.
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 Lengnau (AG) as anywhere.
What are the legal obligations for VAT return 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 Lengnau (AG): federal law applies.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates VAT return for businesses in Lengnau (AG): 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.