
Online accounting for engineering firms in Arbon: rules, deadlines, best practice
Online accounting for engineering firms in Arbon 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.
Digitalising online accounting: 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 Arbon as everywhere.
Electronic archiving is fully recognised: Swiss bookkeeping regulation admits electronic retention of records provided integrity and readability are guaranteed for the 10 years of art. 958f CO. A paper binder is no longer an obligation — provided the archiving system is serious.
Outsource online accounting or keep it in-house?
The Swiss fiduciary market is dense and governed by professional practice: industry standards, business secrecy, civil liability. Compare offers on three concrete criteria — exact scope (data entry? closing? payroll? VAT?), a named contact person, and the tools used. It prevents year-end misunderstandings.
A business in Arbon can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — online accounting splits very well.
The Swiss legal frame for online accounting
Whether a business sits in Arbon or elsewhere in Switzerland, the same federal law applies — one of the strengths of the Swiss system for online accounting. Cantonal differences concentrate on taxation (rates, filing deadlines); bookkeeping itself follows art. 957 ff. CO everywhere.
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.

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 online accounting, valid in Arbon as anywhere.
For online accounting, the right granularity is decisive: enough accounts to steer the business (margins by activity, expenses by nature), few enough that every entry finds its place without hesitation. The VAT accounts (input VAT, VAT due) deserve special care — they are the basis of the annual reconciliation.
Arbon: what changes, what does not
Arbon (postal code 9320, canton Thurgau) applies the same federal rules as the rest of the country: what changes in Arbon are the cantonal counterparts — tax administration, compensation office, commercial register.
For a business in Arbon, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Thurgau.
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 Arbon as anywhere.
Can online accounting be automated with AI?
Largely, yes: automatic document reading, posting suggestions, bank reconciliation via QR references and VAT exports. Human approval remains essential — AI prepares, the professional checks. That is exactly how MyFiducia.ai approaches online accounting.
How much does online accounting cost in Arbon?
It depends on document volume, the number of salaries and VAT complexity — no serious figure can be quoted without examining the file. Two levers cut the bill everywhere: digitised, well-filed receipts and software that prepares entries instead of having them re-keyed.
What are the legal obligations for online accounting 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 Arbon: federal law applies.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates online accounting for businesses in Arbon: 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.