Accounting mistakes often start with a small habit: putting off filing receipts, using the business card for a private purchase, or treating an invoice sent as money already received. Individually, these situations seem manageable. Together, they make the accounts difficult to use.
Key points
- Separate private and business spending, and keep supporting evidence for every transaction.
- Regularly reconcile bank accounts, invoices and accounting entries.
- Do not confuse revenue, profit and cash.
- Software helps you check the figures; it does not decide the correct accounting or tax treatment for you.
Mixing private and business expenses
Paying with a business card does not make an expense deductible. Equally, a business purchase paid personally should not disappear from the accounts: provide the receipt or invoice and identify who paid.
Document the allocation for a phone, vehicle or other mixed-use item. In a sole proprietorship, distinguish private drawings from expenses. In a company, benefits provided to owners or employees require the appropriate treatment.
Set a simple reimbursement and filing rule. Our guide to deductible business expenses explains how to assess the connection with the business.
Find the cause so the mistake does not return
Posting to the wrong account may reflect a misunderstanding. A missing invoice may reveal a collection problem. A duplicate may result from combining an automatic import with manual entry. Correcting the amount is necessary; understanding the process that produced it helps prevent a repeat.
When a difference appears, find the document and follow its path: who received it, how it was recorded and how payment was matched. This is often more effective than searching randomly through every account.
Keep discussions with the team factual. The aim is reliable work, not to discourage people from reporting a problem. An issue raised promptly is usually easier to correct than one left until year end.
Distinguishing business expenses from private spending
Which expenses can a Swiss LLC or SA/AG pay? This French-language video explains the link to the business and the main checks before recording an expense.
Explore the Entreprendre en Suisse avec Sarah et Romain channel (French) →
Recording transactions late or losing supporting documents
Three months after a payment, remembering what it covered becomes difficult. Schedule regular time to collect invoices, check evidence and resolve unidentified transactions.
A bank description is not always sufficient evidence. Keep the invoice or appropriate document with a reference linking it to the entry. A file called “scan-final-2” is little help when searching for a supplier six months later.
Use shared filing and suitable backups. Check that you can export and read the documents if you change software or accountant.
Confusing a sale with its payment
Under accrual accounting, a CHF 5,000 sale may increase profit before the customer pays. The later payment clears the receivable; it does not create a second sale. Spending the money before receiving it can leave the bank account overdrawn despite a profitable month.
A sole proprietorship keeping simplified income-and-expenditure records follows a different recording process. It still needs to track open invoices and its financial position. Identify your business’s accounting regime first, then apply the method consistently.
Track outstanding invoices and due dates, then match incoming payments. Do the same for suppliers: a liability has not disappeared simply because the invoice is no longer in your inbox.
Tracking customer payments and preparing a cash-flow budget answer these questions better than revenue alone.
Correcting a sale recorded twice
Example excluding VAT, using double-entry bookkeeping. A CHF 5,000 invoice is first recorded as sales revenue and a customer receivable. When payment arrives, a bank rule incorrectly creates another sale instead of clearing the receivable.
| Step | What appears in the accounts |
|---|---|
| Invoice issued | Customer receivable: +CHF 5,000; sales: +CHF 5,000. |
| Payment recorded incorrectly | Bank: +CHF 5,000; sales: another +CHF 5,000. The customer balance incorrectly remains open. |
| Correcting this error | Debit sales CHF 5,000 / credit trade receivables CHF 5,000: remove the duplicate sale and clear the customer balance. |
The correction does not change the bank balance: the payment was real. Keep evidence supporting the adjustment. First identify the entries actually posted; this correction is not a universal recipe for every duplicate.
Match each error to a specific check
| Error found | Check to perform | Effect on the accounts |
|---|---|---|
| Sale recorded again when paid | Match the invoice, payment and customer balance | Revenue overstated and a receivable incorrectly left open |
| Annual insurance left entirely in expenses | Read the coverage dates at year end | Expense allocated to the wrong financial periods |
| Sole proprietor’s private purchase recorded as a business expense | Review the evidence and actual use | Business expenses overstated, with a risk of a tax adjustment |
An unintentional error calls for a documented correction. Finding it does not, by itself, establish deliberate fraud.
Our free invoicing software helps you prepare invoices and track outstanding balances. This makes it easier to distinguish a sale from its payment and identify customers to follow up.
Using a VAT rate or method without checking it
VAT mistakes may involve registration, the nature of a supply, the rate, input tax or the reporting period. Cross-border transactions particularly need to be checked against the relevant rules.
Distinguish the VAT calculation method from the reporting basis. Reporting on agreed consideration or consideration received is not simply a choice based on your bookkeeping spreadsheet. Using consideration received, commonly called cash-basis VAT reporting, requires the relevant Federal Tax Administration (FTA) authorisation.
Configure the software after clarifying these choices. Copying another entrepreneur’s settings is unreliable, even if their business appears similar.
Misclassifying purchases and year-end adjustments
A long-lasting asset is not necessarily an expense to deduct in full on the purchase date. An invoice received after 31 December may relate to the year just ended. A known liability is not a provision merely because it will be paid later.
Review fixed assets, depreciation and accruals during the year-end close. Apply a consistent policy and have unusual transactions checked.
Keep a clear trail when correcting an entry. Deleting a transaction without explanation may remove the apparent difference while making the file impossible to follow.
Trusting automation without reviewing it
Invoice recognition can misread a date or amount. A bank rule may allocate every purchase from one supplier to the same account even though the purchases serve different purposes. Two imports can create duplicates.
Review suggestions, duplicates and balances. A monthly check of unusual accounts and comparison with the previous period often helps spot errors early.
A bank reconciliation explained through two differences
The software shows CHF 12,450 in the bank account, while the statement for the same date shows CHF 12,000: a CHF 450 difference. Reviewing the transactions reveals CHF 50 of unrecorded bank fees and a CHF 400 supplier payment missing from the accounts.
Recording both correctly brings the ledger into line with the statement: CHF 12,450 − 50 − 400 = CHF 12,000. But the entries differ. Bank fees are an expense; the supplier payment reduces a liability if the invoice has already been recorded. Treating that payment as a new expense would create another error.
Do not correct a difference with one blanket entry merely to make the balances agree. Each difference needs an explanation and supporting evidence or a verifiable trail.
If the error concerns a closed period or a return already filed, determine the correction method before acting. The consequences may extend beyond the bank account. Keep the link between the original transaction and its correction so another person can understand what changed.
Fix the software settings after correcting the entry
A bank rule allocated an electricity bill to the wrong account. Correcting the entry fixes that month, but the same rule may repeat the error next month. Check the underlying cause: a supplier-to-account rule, default VAT code, repeated import or missing approval.
Before changing a rule, check whether it suits every transaction it recognises. One supplier may sell equipment, maintenance and subscriptions. A rule based only on the supplier’s name can confuse these purchases.
Work in three steps: document the corrected case, adjust the rule or control, then check the first subsequent transactions. If several months may be affected, narrow the review by supplier, period and entry type. This also avoids changing correct transactions in bulk.
A correction log can stay simple: original transaction, reason, corrective entry, person responsible and date. It should let the next reader understand the change without repeating the investigation.
Missing deadlines and waiting too long to ask for help
Keep VAT, payroll, social insurance, tax, year-end and accounts-approval deadlines in one calendar. Assign each task to a person, even when several advisers work on the file.
Seek advice before a significant or unusual transaction: an investment, shareholder funding, a first employee or a change of legal structure. Targeted advice can avoid reconstructing an entire year’s accounts.
Our guide to Swiss VAT mistakes and corrective returns explains return corrections.
Four accounting mistakes that can also create a tax cost
In a Swiss LLC or SA/AG, a benefit granted to an owner can be more than a classification error. Prioritise the following checks.
| Situation | Check and indicative amount |
|---|---|
| The company lends to an owner without charging interest | For a CHF loan funded by the company’s equity, with no interest payable on borrowed capital, the FTA’s minimum safe-harbour rate for 2026 is 0.75%. On CHF 50,000, this is CHF 375 a year. The calculation differs if the company itself uses debt financing. |
| The company pays excessive interest to an owner | For an operating loan in CHF from an owner to a commercial or industrial business, the maximum 2026 safe-harbour rate is 3.5% up to CHF 1 million. Add together loans from all owners and related parties when assessing that limit. On CHF 100,000, 5% costs CHF 1,500 more per year than 3.5%. A higher rate requires evidence supporting an arm’s-length market rate; other situations have their own rates. |
| The company records a private purchase as an expense | Identify the beneficiary and apply the correct treatment: reimbursement, remuneration or distribution, depending on the facts. A benefit to an owner may lead to a tax adjustment and withholding tax. |
| Private use of a company car is omitted | Under the applicable flat-rate method for an employer’s vehicle also used privately, the monthly benefit is 0.9% of the purchase price excluding VAT, with a CHF 150 minimum. For CHF 50,000 excluding VAT, this is CHF 450 a month. This is the benefit to account for, not the tax payable. |
The loan rules appear in the FTA’s 2026 circular (French). Where a taxable benefit constituting a hidden distribution is identified, 35% withholding tax applies to that benefit, not automatically to the entire loan. For vehicles, use the FTA salary certificate guidance (French) and check the conditions of the method applied.
Catching up on overdue bookkeeping in four steps
- Start with banks: obtain every statement, match each transaction and isolate unexplained items.
- Then invoices: rebuild customer and supplier lists, match invoices to payments and look for duplicates.
- Track missing documents: list the document requested, the responsible person and a follow-up date. Do not invent an expense to clear a difference.
- VAT and year end: reconcile returns with the corrected accounts and submit the required amendments. Use the year-end accounts timetable to manage deadlines.
If you plan to keep your own books, choose a process that suits your time and experience. Catching up does not replace a monthly routine. Our Swiss small business accounting guide explains the basics.
Put a few checks in the right places
A monthly checklist to keep beside your accounting software
| Check | How do you know it is complete? |
|---|---|
| Bank and petty cash | Every difference from the statement or cash count is explained, not merely offset. |
| Customers and suppliers | Payments are matched; overdue balances, duplicates and expected credit notes are identified. |
| Supporting documents | Each transaction has evidence or appears on a list of documents to obtain. |
| Private spending, payroll and VAT | Unusual transactions and automatically suggested codes have been reviewed. |
| Deadlines and questions | Each return and unresolved issue has an owner and a due date. |
A tick should point to a statement, list or comment. In a very small business, the owner can perform this review. Where someone else enters the transactions, a second review helps catch familiar mistakes.
Centralised documents, regular bank reconciliation and a review of open invoices already detect many errors. Add checks for the particular risks of your business.
Our accounting team can help resolve differences and organise a process that makes anomalies easier to identify and explain.
Frequently asked questions
Does every accounting mistake lead to a penalty?
No. The consequences depend on the nature and effects of the error. Correct it promptly and check whether a return or declaration also needs amending.
Is accounting software enough to keep accurate accounts?
It helps organise information and calculate totals, but accuracy depends on the supporting documents, settings and accounting decisions.
Which checks should I prioritise each month?
Reconcile the bank, review open invoices and investigate unsupported transactions. These three checks cover a substantial share of common mistakes.
Can I delete an incorrect accounting entry?
The correction must remain clear and traceable. Identify the supporting document and entries, use the software’s appropriate correction process and retain the reason. For a closed period or a return already filed, establish the consequences first.
Why does the bank balance not tell me the profit?
Bank movements also include loans, capital contributions and repayments. Profit can include unpaid sales and expenses not yet paid. Reconcile profit, open invoices and financing movements to understand cash flow.
Sources and references
Romain Prieur is a Swiss Certified Public Accountant and founder of Entreprendre.ch. With more than ten years of experience in audit and business advisory in Switzerland, he advises entrepreneurs on company formation, accounting and tax.
