Separating Personal and Business Finances in a Swiss Einzelfirma

In a Swiss Einzelfirma, money moving between you and the business is not automatically a sale or an expense. Because the proprietor and business are not separate legal persons, sound bookkeeping depends on classifying each transaction correctly—not on calling every transfer a salary.

Why the separation matters

SECO’s SME Portal says sole proprietors are entitled to business profits, but private and professional assets and expenses must be distinguished. Profit enters the owner’s personal tax position, unlike that of a separately taxed company.

You can deduct genuine business expenses from business revenue; you cannot deduct personal spending by routing it through a business account. Misclassification distorts profit, makes cash flow harder to understand and can produce incorrect figures for your tax return.

Some purchases serve both purposes: a vehicle, phone or room at home, for example. SECO notes that mixed private and professional assets should be allocated proportionally. Keep a brief record of your method and apply it consistently rather than guessing again at year end.

This guidance is for a sole proprietorship. A GmbH or AG is a separate legal entity, so personal payments, expenses and withdrawals follow different accounting treatment. If you operate through a company or share costs with others, ask your fiduciary before using an Einzelfirma workflow.

Classify money moving between you and the business

A dedicated business account and card simplify reconciliation, but do not determine deductibility. Save invoices and receipts, and note each transaction’s purpose. A separate account helps control, but does not replace evidence.

A transfer from the business account to your private account is an owner withdrawal, not a supplier cost or payroll expense. It reduces the business’s cash balance, but it does not reduce its profit. Record it in a clearly labelled owner or private account.

Money you put into the business from personal funds is an owner contribution, not sales revenue. Note the date and amount, and keep any related evidence. Do not add the deposit to turnover merely because it appears on the business bank statement.

If you pay a business invoice personally, record the purchase once as a business cost and show it as privately paid or owed to you. Keep the supplier invoice and ask your fiduciary which owner-account entry fits your method.

Handle receipts, mixed use and MWST carefully

Keep the itemised invoice or receipt, not just a card slip. If the business purpose is unclear, note the related client meeting or project so the classification remains understandable later.

For mixed use, record a reasonable business share and its basis, such as business mileage or a usage estimate. Apply the method consistently and note any material change in use.

If you are registered for MWST, the Federal Tax Administration describes input-tax deduction for VAT on purchases used for your own commercial, taxable activity. A business bank account does not make private-use VAT deductible. Keep the invoice and check the correct treatment for mixed or exempt use with the FTA or your fiduciary.

If you are not VAT-registered, do not book supplier VAT as recoverable input tax. Record only the business-related cost under your applicable bookkeeping method. If you are unsure about registration or a private-use adjustment, check current FTA guidance before filing rather than copying last year’s treatment.

Use a repeatable month-end routine

Once a month, match business bank and card transactions to invoices, receipts and customer payments. Label each line as business income, business cost, owner withdrawal, owner contribution or transfer between accounts. Investigate unexplained entries while the details are still fresh.

List business purchases paid personally. Enter each once, attach the receipt and record the owner contribution or amount owed. When reimbursing yourself, match the payment to that entry rather than recording the cost again.

Before month-end, check mixed-use allocations and missing documents. Separate private purchases even on the same statement, and flag unusual or high-value items. Consistent records clarify operating costs and available cash.

At year end, reconcile the owner or private account with your equity records and make sure withdrawals have not been included among deductible expenses. SECO’s guidance on closing a sole proprietorship’s accounts explains the distinction. Keep supporting records, and confirm your filing obligations with your canton or fiduciary.