Connecting your online shop to your invoicing without re-entering the orders

A shop order and a Swiss invoice do not carry the same fields

An order recorded in WooCommerce, Shopify or PrestaShop describes a basket, a delivery address, a shipping method and a payment collected or pending. A Swiss invoice demands something else: an identified debtor, lines attached to an account and to a VAT code, a structured payment reference and, in most cases, a compliant QR section. The two objects look alike on screen and diverge in the detail. It is in that gap that Monday morning's re-entries take up residence.

Three flows actually circulate, and they share neither the same rhythm nor the same direction. The first comes down from the shop to the management software, carrying the orders and the customers. The second goes up from the software to the shop, carrying the items, the prices and the available quantities. The third links collection to the accounts, through the bank account, through the payment provider, or through both. A chain that handles only the first flow leaves the catalogue, the quantities and the collection to be done by hand.

Before any technique, a management decision is unavoidable: knowing where the reference for each piece of data lives. Is the catalogue kept in the shop or in the software, does the selling price prevail on the commerce side or on the management side, does the customer number come from the site or from the existing database. As long as that question stays open, two systems write the same data and nobody knows which one is right on the day they differ.

What a ready-made connector really takes over, and what stays on the quay

Several vendors publish shop connectors. Abacus announces Shopify, WooCommerce through pingWoo, Magento and PepperShop. SelectLine announces Shopware, Shopify and Venabo. WinBIZ publishes a WooCommerce connector, a PrestaShop order link and a Sempio connector. Infoniqa lists a directory of 175 third-party links, 159 of them declared compatible with ONE 50. Odoo occupies a different position, shop and management living in the same system, which shifts the question from the interface to the functional scope.

What these connectors cover is real and useful: taking over the orders, creating or updating the customer, creating a commercial document, often reporting the quantities back. What they rarely cover sits in the details that make up the exact turnover. The generic connector handles the nominal case, a simple order, paid, delivered in one go. It is the orders that depart from that nominal case which take up time every week.

Before signing, the connector's data sheet must therefore be read line by line and every field set against your orders of the last twelve months. A connector that takes over the bulk of the orders without intervention still leaves a daily queue of special cases, and that queue costs more in attention than in minutes.

• Item variants, size, colour, packaging, and their correspondence with a unique item code
• Line-level discounts, vouchers and prices by customer group
• Shipping and handling costs, with their own VAT rate
• Deposits, partial payments and renewed subscriptions
• Returns, credit notes and partial refunds from the payment provider
• Orders in several currencies and exchange costs

Shipping costs, deposits and returns make the total diverge before the accounts

VAT is the first point of friction. The rates in force since 1 January 2024 are 8,1 % for the standard rate, 2,6 % for the reduced rate and 3,8 % for accommodation, and Swiss vendors document how they handle them, WinBIZ for instance on the official forms of the Federal Tax Administration. The question is not there. It is knowing what rate the shop applies to shipping costs, how it treats an order outside Switzerland, and whether displayed prices are entered inclusive of VAT on one side and exclusive on the other.

The second point of friction is collection. A payment provider rarely pays over the amount of the order; it pays a net balance, in batches, after deducting its commissions and the period's refunds. The accounts expect the opposite: an invoice, a receipt, a fee entry. Without a reconciliation rule established in advance, the bank account and the general ledger drift apart a little every week, and the closing is left to work out why.

The third point is the goods return. A refunded customer produces three distinct events: a stock movement, a credit note, and a financial refund. A shop manages that in its own vocabulary, management software in its own. Deciding how one translates into the other is design work, and that work is done once, calmly, rather than case by case.

Two stocks for a single item, and the question of which one prevails

An SME that sells in a shop and online holds two counters for the same item. The problem is not making them equal at a given instant, it is defining who describes the truth between two synchronisations and what happens when both fall at once. The answer depends on your trade, on the preparation lead time, on volume, and on whether an occasional stock-out is acceptable.

The software's scope counts more here than the connector. At bexio, the management of batches, serial numbers and several warehouses is not documented in the vendor's help on the day of reading, and the product import is reported as capped at 15'000 lines. SelectLine announces production and commercial management, Infoniqa ONE 200 logistics and controlling, Odoo stock and production in the same system. SelectLine is deployed on a Windows server with Microsoft SQL Server, the Infoniqa suites are installed at the client's, and implementing Odoo generally goes through a partner. Choosing stock depth is a decision that comes before the choice of connector, not after.

Finally, reservation deserves to be set down in black and white. Should a quantity leave the available stock at the moment of the order, of the payment, or of the shipment. The choice bears directly on the number of orders you will not be able to honour, and it is written the same way in both systems, failing which it means nothing.

Without a webhook, synchronisation becomes a matter of frequency

A webhook is a call the vendor sends to your system at the moment something changes. Without it, the only route left is periodic polling: your program regularly asks what has moved. bexio's public documentation read on 23 August 2026 contains no webhooks section, smallinvoice's exposes no callback path, and searching for the term in WinBIZ's help centre returns nothing. Odoo announces webhooks, and AbaNinja announces them from its Basic plan.

Periodic polling is not a stopgap, it is an architecture that has to be sized. You have to choose a frequency, hold to the pagination the vendor imposes, up to 500 items per request at bexio, a means of spotting what has changed, a memory of what has already been handled, and a course of action when a call fails. KLARA's documentation states that a rate limit exists, with a 429 response, without publishing either the threshold or the window, which makes theoretical calculation impossible and forces a measurement.

One last detail weighs heavily in operations. KLARA's documentation also states that there is no separate test environment and that every call works on production data. That changes the way one builds: you write reads first, you log, you replay dry, and only then do you write.

What we establish before writing the first line of code

We sell no licences. We therefore start from your real orders, not from the connector's data sheet. A sample of the orders of the last twelve months shows the share of simple baskets, that of orders with unusual shipping costs, that of returns and that of the cases nobody had mentioned. That count steers the rest: it says whether a standard connector is enough, whether it must be supplemented, or whether it is better to write directly against the API.

We then check the technical access conditions, in the vendor's documentation read on 23 August 2026 and not in its brochure. SelectLine's API is included from the Premium edition and assumes the installation of the Mobile Manager and the Toolbox. Odoo Online's is open only on the Custom plan. At WinBIZ, the documentation states that the API key is obtained by being a partner under the general partnership terms. At Crésus, exchanges go through import and export templates in text and in CSV.

Then we write the acceptance test before the mechanics. A test order with a variant, one with shipping costs, one with a deposit, one with a partial return, one outside Switzerland, each with the result expected in the management software and in the accounts. On the day the chain runs, that test set becomes the check you relaunch after every update of the shop or of the software, and it belongs to you.

Where these answers come from

Every fact on this page can be checked at the source. The links open directly the website of the vendor or body concerned.

• bexio API documentation, REST and JSON, OAuth 2.0 and OpenID Connect, pagination up to 500 items, no webhooks section as of 23.08.2026Access conditions to bexio's API and absence of webhooks in the documentation read
• KLARA developer documentation, absence of a separate test environment, 429 response with no published thresholdOperating constraints of a synchronisation by periodic polling
• smallinvoice pricing, FREE plan, STARTER at CHF 15 per month with API access includedEntry cost of API access on a Swiss invoicing solution
• Odoo external API, data access reserved for the Custom plans on Odoo OnlineCondition for opening the API according to the subscription plan
• SelectLine API online help, ERP scope, Mobile Manager and Toolbox prerequisites, no webhook documentedTechnical prerequisites of a SelectLine integration
• SelectLine subscriptions in Switzerland, API included from the Premium edition at CHF 119.- per user per monthMinimum edition giving access to the API
• WinBIZ help centre, obtaining an API key conditional on partner status under the general partnership termsAccess condition to WinBIZ's API
• WinBIZ product page, VAT statements on Federal Tax Administration forms with the 2024 rates, standard 8,1 %, reduced 2,6 %, special 3,8 %Swiss VAT rates supported and functional scope
• AbaNinja, Starter, Basic and Pro plans, API and webhooks announced from the Basic planCase of a Swiss vendor documenting webhooks
• Specifications of Crésus Invoicing, exchanges through import and export templates in text and in CSVNature of data exchange in the absence of a documented public API
• Connectors announced by Abacus, including Shopify, WooCommerce through pingWoo, Magento and PepperShopScope of the online commerce connectors announced by the vendor
• Official Infoniqa directory of third-party links, 175 solutions of which 159 declared ONE 50 compatibleEcosystem of named bridges around ONE 50

SURVEY OF 23.08.2026

Frequently asked questions