Why B2B orders end up in chat
In many Swiss SMEs — wholesale, crafts, B2B services, local distribution — the order no longer goes through an e-procurement portal but through a voice message, a photo of the price list or an “ok, send me 50 units at CHF 12”. WhatsApp, Signal, Telegram and messaging built into collaboration platforms have reduced friction and response times, especially with regular customers who trust the commercial relationship.
Under Swiss law of obligations, the form of a contract of sale or for services is in principle free: what matters is the parties’ agreement on performance and consideration. A message can therefore serve as proof of a binding order, provided you can show who wrote what, when and with what authority. The issue is not only “is it valid?” but “can it be reconstructed in accounting, in audit and before the Federal Tax Administration (FTA) for VAT?”.
This guide links operational use of messaging apps, bookkeeping obligations (Swiss Code of Obligations and Swiss accounting standards) and the VAT document chain, with a practical path for business owners, administrative managers and trust firms supporting SMEs in Switzerland.
Chat vs formal requirements: what the law expects
A message can initiate or confirm a commercial relationship, but it does not automatically replace all accounting and tax compliance. Summary for guidance (not exhaustive):
| Aspect | In-app message | Accounting / VAT expectation |
|---|---|---|
| Contract formation (CO) | Agreement by message often sufficient if essential elements present | Clear content: what, quantity, price or reference to price list/framework contract |
| Evidence and date | App timestamp; risk of edits/deletions | Company archive with reliable date (export, ERP, archived confirmation email) |
| Bookkeeping (CO) | Not in itself a ledger | Every transaction must be recordable and reconstructable afterwards |
| VAT invoice (VAT Act) | Chat order is not the invoice | Billing document with legal requirements (Art. 26 VAT Act); link order → delivery → invoice |
| Input VAT deduction | Chat alone is not enough for the buyer | Compliant supplier invoice; traceability of taxable supply |
| Retention | Depends on phone and app policies | Accounting records and supporting documents kept for ten years from end of financial year (Art. 958f CO) |
| Data protection | Personal numbers, content, mixed B2B/B2C groups | FADP: legal basis, minimisation, company channels where possible |
Validity of B2B orders sent via messaging
For a typical B2B order between traders or professionals, the Code of Obligations does not require written form. Exceptions and precautions remain:
Minimum elements. A vague message (“I still need the usual ones”) creates uncertainty on quantity, price and terms. Better a text that specifies item or service, quantity, unit price or explicit reference to quote/price list/framework contract, place and mode of delivery, desired date if any.
Who speaks for the company. In SMEs the WhatsApp number is often the owner’s or a sales rep’s. In a dispute you must show the sender had authority to represent or internal mandate. Internal policies (who may accept orders, maximum amounts) reduce the risk of unauthorised commitments.
Special forms. Some sectors or clauses (e.g. written-form requirements in framework contracts, particular guarantees) may require different documents. For real estate, certain assignments of receivables or complex agreements, chat is not the right tool.
Evidential weight. Swiss courts assess messages like other evidence. Full exports, screenshots with weak metadata or partial conversations carry less weight than a flow with confirmation email, numbered order in ERP and consistent invoice.
Common scenario
The customer sends on WhatsApp: “I confirm the order of 15.03, 200 units ref. ABC, price as per quote P-2026-041, delivery Zurich warehouse”. The supplier replies: “Received, order OR-8842, delivery expected 22.03”. If OR-8842 is recorded in ERP and the invoice repeats the same data, commercial validity and accounting traceability reinforce each other.
Accounting traceability: from message to ledger
Art. 957 et seq. CO requires accounts to be kept so that every business transaction is verifiable. Swiss accounting principles (Swiss GAAP FER / rules relevant to entity type) require supporting documentation and links between entries and vouchers. A WhatsApp thread scattered on private phones does not alone meet this standard.
Seller side
- Centralised order numbering (ERP, invoicing, Accountex)
- Record receipt of payment only against identifiable order/invoice
- Attachment or link to supporting document (PDF chat export, confirmation email)
- Consistency between order date, delivery date and accrual period
Buyer side
- Internal order or purchase request linked to supplier message
- Three-way match: order, goods/service receipt, invoice
- Single archive for internal or fiduciary audit
- Avoid sales being the only holder of proof on a phone
Accounting software such as Accountex does not replace proof of the initial agreement, but it is where order, invoice, payment and customer balance must converge. The operational goal: every revenue or cost posted has a readable reference (order number, customer, period) and a retrievable document within minutes.
VAT risks: where chat creates gaps in the chain
For value added tax, an order via messaging is a preliminary commercial step. The event relevant for settlement remains the taxable supply and the invoice (or equivalent document) that meets the requirements of the VAT Act and ordinance.
Taxable supplier. Issuing invoices with incomplete data, wrong rate or no clear reference to the supply because “everything was on WhatsApp” exposes you to adjustments, interest and challenges in an audit. Chat does not exempt you from correct documentation when an invoice is required or issued.
Buyer seeking VAT deduction. Deduction of input tax (Art. 28 VAT Act) requires an invoice compliant with Art. 26 VAT Act — as a rule to be requested from the supplier — and proof that the supply was received within the business activity that entitles deduction. Messages without a compliant invoice do not create a right to deduct.
Date of supply. Disagreement on “when” something was ordered or delivered affects the VAT reporting period (and indirectly monthly or quarterly closing). Chat timestamp + documented delivery date + aligned invoice avoid double periods or omissions.
Last-minute discounts and changes. “Take off 10% as agreed on WhatsApp” with no trace on invoice or credit note creates mismatches between consideration received and taxable amount declared.
Cross-border supplies. B2B orders via chat with EU or non-Swiss customers do not simplify rules on place of supply, reverse charge or declarations: contracts, VAT numbers and consistent documents are still required.
| Risk | Typical signal | Mitigation |
|---|---|---|
| Underdeclared tax base | Deliveries made, invoices issued only partly | Mandatory order in ERP before fulfilment; check open orders vs invoiced |
| Deduction challenged | Invoice lacking detail; no proof of goods receipt | Goods receipt process; link chat order → internal PO → invoice |
| Wrong VAT period | Order at month end, delivery early next month | Internal rule on supply date; documented cut-off at closing |
| Wrong rate | “All-in” price in chat without specifying rate | VAT-ready price lists; written confirmation of rate on sensitive products (food, accommodation, etc.) |
Recommended flow: fast chat, solid proof
The goal is not to ban WhatsApp but to prevent it from remaining the only information system. A model suited to many SMEs:
- Intake. Sales accepts the message but always replies with a provisional order number or a request to confirm missing data.
- Recording within 24 hours. The order enters ERP/accounting with customer, estimated amount, VAT rate and reference “WhatsApp channel” + message date.
- Light formal confirmation. Automatic email or PDF “order confirmation” sent to the B2B contact (even if the order originated in chat).
- Archive. Periodic export of relevant chats (WhatsApp Business) to company storage with retention policy aligned to the ten-year term from end of financial year (Art. 958f CO), or preferably only confirmation PDF + attachments in ERP.
- Invoicing. Invoice generated from order; any post-chat changes via credit note or documented new line.
- VAT closing. Monthly reconciliation: open orders, invoices issued, receipts; anomalies flagged before filing.
WhatsApp Business vs personal accounts
Business accounts with company label, backup where IT allows and separation from the owner’s private phone improve continuity (staff turnover, lost devices). Avoid informal groups mixing orders, complaints and private conversations: in audit, filtering what you need becomes costly.
Internal policy, FADP and audit
A brief written directive — even one page — should define: which roles may conclude orders on chat, amount limits, obligation to enter orders in ERP, ban on deleting commercial conversations before the agreed retention period, and preferred use of company channels (traceable company email, order portal) for strategic customers.
Under the Federal Act on Data Protection, processing phone numbers, names and order content requires informing data subjects when necessary, limiting access to threads and not forwarding full chat exports to unsecured personal email. Auditors (internal, fiduciary or statutory) will ask for samples: order → fulfilment → invoice → payment. If the sample runs through an untracked phone, confidence in internal control drops.
For trust firms, standardising a checklist in client onboarding (“how do B2B orders arrive?”) avoids surprises at year-end, when thousands of unarchived messages slow and costly closing.
Operational checklist for management
- ✓Every order accepted via chat has a number in ERP by the next business day.
- ✓Order confirmation (email or PDF) sent to customer with summary of quantities, prices and VAT.
- ✓Invoices issued only from registered orders; post-chat discounts documented with credit note or adjustment.
- ✓Export or central archive of critical commercial conversations, not only on a phone.
- ✓Monthly reconciliation of orders / invoices / VAT before submitting the periodic return.
- ✓Policy on signing authority and maximum amounts for orders via messaging, communicated to the sales team.
In summary
B2B orders via WhatsApp and other messaging apps are compatible with Swiss commercial practice if the agreement content is clear and the company quickly translates chat into numbered, retained documents aligned with invoicing. The main risks are not message “invalidity” but lack of accounting traceability, VAT period errors and invoices disconnected from the actual supply.
By integrating fast channels with structured accounting ERP — order entry, invoices, receipts and liquidity reports in one flow — SMEs keep the agility of direct customer contact without weakening accounting compliance (CO), VAT and auditor scrutiny. That balance, more than the choice of app, separates an informal habit from a sustainable B2B process.