
E-invoicing for SA companies in Lengnau (AG): the practical guide
E-invoicing for SA companies in Lengnau (AG) 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.
Digitalising e-invoicing: what actually works
Security is part of digitalisation: named access, tested backups, encryption of sensitive data. A digital accounting file is protected like a safe — because it is one.
The winning pair for e-invoicing: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.
QR-bills and friction-free collections
Instalments and partial payments are handled cleanly with distinct references per tranche: each collection finds its share, and the remaining balance stays correct at all times.
The winning trio remains: QR-bills for collections, e-banking connected to the accounts for statement imports (camt.053), and automatic matching rules. Exceptions — partial payments, duplicates, missing references — are then handled in minutes, not hours.
The Swiss legal frame for e-invoicing
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. E-invoicing sits squarely within this frame, including for companies based in Lengnau (AG).
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.

A well-structured SME chart of accounts
A chart of accounts gets documented: one description line per account (what, when, VAT) is enough for two people to post the same way. It is the quality manual of e-invoicing, valid in Lengnau (AG) as anywhere.
The chart of accounts is also the hinge to VAT: every revenue account carries its rate (8.1%, 2.6%, 3.8% or exempt), every expense account its input-tax right. Set those attributes once in the tool and every subsequent return becomes reliable.
Lengnau (AG): what changes, what does not
Working with a fiduciary from Lengnau (AG) no longer depends on geography: the documents of a business in Lengnau (AG) are shared online, while the canton Aargau keeps its own deadlines for the tax return.
For a business in Lengnau (AG), that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Aargau.
Frequently asked questions
What are the current Swiss VAT rates?
Since 1 January 2024: 8.1% (standard), 2.6% (reduced — for example food and medicines) and 3.8% (accommodation). Returns must be filed and paid within 60 days after the period ends (quarterly under the effective method, semi-annually under the net tax rate method). These federal rates apply unchanged in Lengnau (AG).
Do you need a fiduciary for e-invoicing, 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 Lengnau (AG).
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 Lengnau (AG), family allowances follow the canton's rates.
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 Lengnau (AG) as anywhere.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates e-invoicing 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.