Why duplicate payments often stay hidden
In Swiss SMEs, duplicate supplier payments are not uncommon: the same invoice paid twice, a transfer repeated after a reminder, or a duplicate accounting entry while the bank account shows only one payment. The error may originate in administration, invoice approval, or handoffs between tools (e-banking, OCR, exports to accounting software).
As long as bank reconciliation stays superficial, the overpayment often remains on clearing accounts or the supplier balance, eroding liquidity without showing up immediately in the income statement. Recovering the amount requires traceability (invoice number, QR reference, value date) and an accounting correction consistent with applicable Swiss accounting standards (typically Swiss GAAP FER for SMEs).
This guide explains how to identify duplicate payments, start recovery with the supplier, and record adjustments in an auditable way—with attention to VAT and year-end closing deadlines.
Typical causes in supplier processes
Before correcting the figures, classify the source of the error: accounting treatment and evidence to retain depend on the case.
| Scenario | Operational signal | Accounting risk |
|---|---|---|
| Duplicate transfer on the same invoice | Two outflows with the same amount and similar reference | Unreconciled credit with supplier |
| Invoice paid then reopened | “Open” status in ERP despite bank debit | Expense or deductible VAT booked twice |
| Deposit and final balance confused | Deposit not applied to final balance | Double charge on the same purchase commitment |
| Duplicate supplier master record | Same UID/IBAN on two supplier codes | Payments allocated to the wrong account |
| Credit note not recorded | Abnormally positive supplier balance | Credit not offset against new invoices |
Finding errors: targeted controls
A mix of automated checks and human review shortens the time between a duplicate payment and confirmation.
Bank reconciliation
Match every outflow to an open invoice, QR reference number, and value date. Flag identical amounts to the same IBAN within 30–60 days. In Accountex, keep the bank transaction ↔ supplier document link for every payment.
Open items on the suppliers account (2000) or clearing accounts should have an aging list: credits with suppliers older than 90 days deserve priority review.
Supplier reports
Extract negative payable balances (credit with supplier), invoices paid twice (same document number, two payment postings), and duplicates by amount/date/supplier.
Cross-check with the supplier statement at least once a year for strategic partners and after every balance dispute.
- Four-eyes approval: for payments above an internal threshold (e.g. CHF 5,000), verify the invoice is not already marked “paid” in the workflow.
- Audit trail: retain invoice PDF, transfer confirmation, and logs of who authorized the second payment—useful for audit or dispute.
- Monthly close: before sending reports to management, close anomalous supplier items and document exceptions.
Recovering the overpayment from the supplier
Recovery is first a commercial and administrative process. Act promptly: the more time passes, the harder it is to reconcile accounts and obtain a refund.
Send a written request with invoice number, payment dates, amounts, bank references, and your internal account statement. Explicitly ask for refund to a stated IBAN or offset against future invoices—both are common in Switzerland when documented.
If the supplier offers offset only
Accept offset only if you track the remaining credit in accounting until it is used. Record the credit note or offset letter and apply subsequent invoices until the credit is exhausted. Avoid verbal agreements not reflected in the general ledger.
If the supplier resists, the contractual relationship and proof of overpayment form the basis for formal reminders and, where the conditions are met, an action for unjust enrichment (Art. 62 et seq. CO). For material amounts, involve legal counsel before proceedings that may cost more than the amount at stake.
Correcting the accounts: typical entries
Entries must reflect economic reality: credit with the supplier until refund or offset arrives; no double deduction of cost or VAT.
| Timing | Logic | Schematic example (CHF) |
|---|---|---|
| Duplicate payment identified | Recognition of credit with supplier | Debit credits with suppliers / Credit bank (overpayment amount) |
| Expense already booked twice | Reversal of duplicate cost | Debit supplier or expense account / Credit duplicate expense account |
| Refund received | Clearing of the credit | Debit bank / Credit credits with suppliers |
| Offset against new invoice | Application of remaining credit | Debit supplier (invoice) / Credit credits with suppliers (portion) |
Use a dedicated clearing account (e.g. “Supplier recoveries receivable”) only if the chart of accounts provides for it and you monitor balances at monthly close. Prior-year adjustments, if material, should be assessed under applicable error-correction principles and, where necessary, with the auditor.
VAT and returns: avoiding double deductions
If the duplicate payment coincided with duplicate purchase posting, input tax may have been deducted twice in the VAT return. Correct in the reporting period when you discover the error, with documentation linking the accounting reversal and tax adjustment (Art. 28 and Art. 72 VAT Act, and the obligation to file a complete and correct return under Art. 71 VAT Act).
A supplier refund that includes VAT does not create a new deduction: clear the commercial credit. If you receive a supplier credit note, align document date, net amount, and tax in the VAT registration for the relevant period.
Keep invoices, credit notes, and payment evidence for at least ten years, in line with accounting record-keeping and retention duties (Art. 958f CO) and VAT retention periods (Art. 70 VAT Act).
Prevention: simple, high-impact rules
Single master record
One supplier, one code, one verified IBAN. Block duplicates with UID or VAT number checks.
Invoice status
Workflow “to pay → paid → reconciled”. Prevent a second payment without documented release.
Automatic matching
Bank import with rules on QR reference and amount. Exceptions in a weekly review queue.
Operational checklist
- Reconcile bank outflows and flag duplicate payments before month-end close.
- Document credit with supplier and contact the partner with complete evidence.
- Post reversals to expense/VAT if the spend was duplicated, not only the treasury movement.
- Monitor until refund or offset and close the item with an audit trail.
- Update approval procedures if the error stems from a recurring control gap.
With clear processes and data linked between bank and accounts payable, SMEs recover liquidity lost through error faster and present financial statements consistent with the true balance sheet position—essential for banks, investors, and ordinary or limited audit under the Code of Obligations.