The hidden problem of unrecovered VAT
Every year Swiss companies leave millions of francs in VAT on the table that they would be entitled to recover. According to FTA estimates, between 5% and 12% of input tax deductions are rejected during audits — not for fraud, but for avoidable documentation errors: incomplete receipts, invoices missing minimum requirements, and non-compliant archiving.
For an SME with annual purchases of CHF 500,000 and a VAT rate of 8.1%, this potentially means CHF 2,000–5,000 in lost input tax every year. For companies with higher volumes or international purchases, the figures rise rapidly.
This guide analyses in detail the legal requirements for input tax deduction (Art. 28–30 VAT Act), the most common documentation errors, the receipts accepted by the FTA, and practical strategies for optimizing VAT recovery in your business.
Right to input tax deduction
The input tax deduction (Vorsteuerabzug) is the mechanism that allows VAT-registered businesses to recover the tax paid on purchases of goods and services used for their taxable activity. Art. 28 of the VAT Act defines five cumulative conditions that must be met:
- The business must be registered in the FTA's VAT taxpayer register (Art. 10 VAT Act) — businesses with annual turnover exceeding CHF 100,000 are subject to VAT
- The goods or services purchased must be used for a taxable business activity or one that entitles to deduction (Art. 28 para. 1 VAT Act)
- The VAT must have been actually invoiced and shown separately on the receipt (Art. 28 para. 1 let. a VAT Act)
- The receipt must meet the formal requirements of Art. 26 VAT Act: supplier name and VAT number, date, description of service, VAT amount shown separately
- The deduction must be claimed in the correct reporting period — the statute of limitations is 5 years from the end of the tax period (Art. 42 para. 6 VAT Act)
Documentation errors that cost dearly
During tax audits, the FTA systematically checks receipt compliance. Here are the six most common errors that lead to rejected input tax deductions:
Missing or incorrect VAT number
The receipt does not include the supplier's VAT number (CHE-XXX.XXX.XXX), or the number listed does not match a registered taxpayer. The FTA systematically rejects deductions without this data (Art. 26 para. 2 let. a VAT Act). Always verify on uid.admin.ch.
VAT not shown separately
The invoice shows a total amount 'VAT included' without separately indicating the rate and the tax amount. Even if the VAT was actually paid, without explicit indication the deduction is not allowed (Art. 26 para. 2 let. f VAT Act).
Insufficient service description
The invoice generically indicates 'various services' or 'materials' without specifying the type and scope of the service. The FTA requires a description that allows verification of the commercial nature of the purchase and its relevance to the taxable activity.
Cash register receipts without complete data
Small-amount receipts (fuel, office supplies, business lunches) lacking the buyer's name or the supplier's VAT number. For amounts up to CHF 400 the FTA accepts simplified receipts, but above this threshold all data required by Art. 26 VAT Act is needed.
Receipts not preserved or illegible
Faded thermal receipts, unsaved PDF invoices, documents lost during a software change. Compliant preservation for 10 years (Art. 958f CO and Art. 70 para. 2 VAT Act) is a necessary condition for deduction. Without a legible receipt, no deduction.
Mixed use without apportionment
Purchases used for both taxable and excluded activities (e.g. exempt training, healthcare services) without proper proportional apportionment. The FTA requires a documented calculation method for the deductible portion (Art. 30 VAT Act).
Valid receipts according to the FTA
Art. 26 of the VAT Act and the FTA's related practice define the minimum requirements for each type of receipt. Here is an overview of the most common documents and their standards:
| Document type | Minimum requirements | Accepted format |
|---|---|---|
| Standard invoice | Supplier name/address, VAT no., date, service description, net amount, VAT rate and amount, gross amount, recipient | PDF, paper, XML (e-invoice) |
| Simplified invoice (≤ CHF 400) | Supplier name, VAT no., date, brief description, total amount with indication 'VAT included' and rate | Receipt, PDF, POS receipt |
| Credit note | Same requirements as the standard invoice, with indication of the original document corrected and reason for the correction | PDF, paper |
| Import document | Customs assessment decision, import VAT amount shown separately, BAZG reference number | e-dec (electronic), customs PDF |
| Travel expense receipt | Date, supplier, amount, nature of expense, link to business activity documented (signed expense report) | Original receipt + digital expense report |
Quarterly/semi-annual VAT return
The VAT return (Mehrwertsteuerabrechnung) must be filed with the FTA within 60 days of the end of the reporting period — quarterly for most businesses, semi-annually upon request. Here are the key steps for a correct return:
Receipt collection and verification
Collect all purchase and sales invoices for the quarter. Verify that each receipt meets the formal requirements of Art. 26 VAT Act. Flag and request corrections from suppliers for incomplete invoices before closing the period.
Classification by rate and type
Classify each transaction by the correct VAT rate (8.1% standard, 2.6% reduced, 3.8% hospitality sector) and service type (taxable, exempt, excluded). Incorrect classification distorts both VAT owed and deductible input tax.
Calculation of deductible input tax
Sum the VAT on all purchases that entitle to deduction. In case of mixed use, apply the documented apportionment key. Subtract any corrections for own consumption, business gifts, or private use of business assets.
Completing and filing the FTA form
Complete the return form online (FTA ePortal) or through the accounting software. Key figures: taxable turnover (figure 200), tax owed (figure 399), deductible input tax (figure 400), balance payable/credit (figure 500).
Payment or credit
If the tax owed exceeds the input tax, the balance must be paid to the FTA within 60 days. Otherwise (common for exporting companies or those in an investment phase), the FTA refunds the credit within approximately 30 days of receiving the return.
Watch the deadlines: late filing or payment incurs default interest of 4% per year (Art. 87 VAT Act). For quarterly returns the deadlines are: 31 May (Q1), 31 August (Q2), 30 November (Q3), 28 February (Q4).
Practical cases: VAT lost and recovered
Here are three real-world scenarios illustrating how documentation errors lead to lost input tax — and how to fix them:
Engineering firm — CHF 8,200 in VAT lost on consultancy
The firm receives invoices from foreign subcontractors without a Swiss VAT number and without separate tax indication. Over 3 years it accumulates CHF 8,200 in non-deductible VAT on service purchases of CHF 101,000. The problem is only discovered during an FTA audit.
After implementing an invoice verification checklist and requesting corrective credit notes from suppliers, the firm recovers CHF 5,400 in arrears (within the statute of limitations) and prevents future losses through automatic requirements verification at receipt.
Manufacturing SME — CHF 12,500/year in rejected deductions
The company keeps raw material purchase receipts on thermal paper that becomes illegible after 18 months. During a tax audit, the FTA rejects CHF 12,500 in deductions due to lack of legible receipts. The amount corresponds to approximately 120 purchase receipts from wholesalers.
Immediate digitization of every receipt via OCR at the time of receipt. Images are archived with cryptographic hash and linked to the accounting entry. At the next audit, all deductions are accepted. Annual savings: CHF 12,500.
IT services company — mixed use not correctly apportioned
The company deducts 100% of VAT on office rent and software licenses, but 20% of turnover comes from VAT-exempt training services. During the audit, the FTA recalculates the deduction at 80% and requests a repayment of CHF 6,800 plus default interest for 2 years.
Implementation of a documented apportionment key updated quarterly. The company monitors the ratio between taxable and exempt services, applies proportional deduction, and documents the calculation. No disputes at subsequent audits.
Optimizing VAT recovery
Beyond avoiding documentation errors, there are proactive strategies to maximize recovered input tax:
Automatic receipt verification
Configure your accounting software to automatically verify the presence of mandatory fields (VAT no., rate, separate amount) at the time of entry. Incomplete receipts are flagged before the period closes.
Immediate digitization with OCR
Scan or photograph every receipt within 24 hours of receiving it. OCR extracts data automatically and archives it in an immutable format. No more faded receipts or lost documents.
Pre-return quarterly review
Dedicate 2–3 hours before each return to reviewing the quarter's receipts. Identify incomplete invoices and request corrections from suppliers before the deadline. Better to invest 3 hours than to lose CHF 3,000.
Apportionment key update
If your business has a mix of taxable and excluded activities, recalculate the apportionment key at least annually. A change in the turnover mix can mean thousands of francs more or less in recoverable VAT.
Separate management of imports
For goods imports, systematically retain customs assessment decisions (e-dec) and link each transaction to the accounting entry. Import VAT is often overlooked but represents a significant amount for companies purchasing abroad.
Training for operational staff
Staff who receive and record invoices must know the minimum requirements of Art. 26 VAT Act. A short annual training of 1–2 hours drastically reduces errors at the source and empowers those who handle documents daily.
Practical tips
- Always verify the supplier's VAT number on uid.admin.ch before recording a significant invoice — 10 seconds is all it takes to avoid a rejected deduction
- Keep a digital copy of every receipt immediately: thermal receipts become illegible in 12–18 months and the FTA does not accept faded documents as valid proof
- For simplified invoices (≤ CHF 400), make sure at least the VAT rate and the wording 'VAT included' are shown — many POS receipts do not print this automatically
- Always request a full invoice (not a receipt) for purchases over CHF 400: the marginal cost is zero and the deduction security is much higher
- If your turnover includes VAT-exempt services (training, healthcare, insurance), document and update the apportionment key annually for proportional deduction
- Set an alert in your accounting software 30 days before the return deadline: delays cost 4% per year in default interest
- Use AccountEX to automate VAT receipt verification, rate classification, and quarterly return generation — reduce errors and recover every franc of input tax
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