Connecting Crésus to the rest of your tools when the vendor publishes no interface

Crésus publishes no interface for third parties, and that changes the method

The vendor's documentation, read on 23 August 2026, describes no programmable interface open to an external developer. The API mentions found there go the other way, with the PostFinance API channel and EBICS in Crésus Banking, or the tilbago API key for debt collection. These are outbound channels to partners chosen by Epsitec SA. Any traffic with a trade tool is therefore conceived differently, through files, through a calendar and through a rule of precedence written in black and white.

It is an architectural constraint, and it is dealt with upstream. It rules out second-by-second synchronisation and forces a decision on who holds the reference record for each object: the customer, the article, the entry, the payment. An SME that enters its customers in a quoting tool and finds them again in Crésus Facturation has to choose a single direction of travel, failing which two files drift apart with nobody knowing which one prevails on closing day.

The useful work consists in laying out the map before writing the slightest line. Which objects travel, in which direction, at what frequency, and what happens when a takeover fails along the way. These questions are answered on paper, tested afterwards on a trial data set, and end up in a procedure someone else can replay six months later without phoning you on a Saturday.

The import and export templates are the real interface of Crésus

Crésus exchanges through configurable templates. Text files use the tab as separator, CSV files the semicolon, and both open in Excel without any special handling. A detail that counts a great deal in practice: the import templates are identical to the export templates. The format you carefully built to get data out becomes the one you will be able to read back, which greatly reduces the tuning work and allows checking a complete round trip before going into production.

Accounting accepts importing entries, invoicing accepts importing customer and article lists. A trade tool that produces a clean file, with stable columns and an agreed set of accounts, therefore feeds Crésus without manual line-by-line rework. The delicate point lies elsewhere, in the stability of the source file. Site software that changes the order of its columns after an update breaks the template, often silently.

A well-designed template is documented like a contract. It fixes the column order, the date format, the decimal separator, the treatment of negative amounts and the default contra account. A rule is added for rejected lines, because an import interrupted midway leaves a client file in an intermediate state nobody likes to discover on a Friday evening. This document survives changes of staff, and it is what makes the exchange reproducible.

• Text file with tab separator, readable in Excel
• CSV file with semicolon separator
• Import template identical to the export template, therefore testable both ways
• Importing entries into Crésus Comptabilité
• Importing customer and article lists into Crésus Facturation
• XML ISO 20022 for exchanges with the bank

The Swiss formats travel through the bank and through the SIX network

Payment traffic follows the Swiss standards end to end. Crésus Banking issues orders in pain.001, receives statuses in pain.002, reads movements in camt.053 and QR receipts in camt.054. The QR-bill is covered for issuing as for processing received invoices. These formats are documented and stable, which makes them the most solid route for money in and out without re-entry in an intermediate spreadsheet.

For electronic invoicing, Epsitec SA is registered with SIX as an eBill network partner, and sending leaves directly from Crésus Facturation, at 20 centimes per dispatch before tax. Access assumes an active QR-IBAN, an entry in the commercial register, an issuing contract and registration fees of 20 francs. The vendor's documentation, read on 23 August 2026, describes sending and does not mention receiving eBill invoices in Crésus Facturation.

Peppol calls for more caution. No mention appears in the official documentation read on 23 August 2026, and no Epsitec SA or Crésus entry comes out of the Peppol directory. An SME working with European public principals is therefore better off asking the vendor before any commitment, rather than discovering the subject at the moment a first invoice comes back unaccepted.

Where the file rests decides how solid the set-up is

The vendor is explicit on a point many companies learn too late. Crésus files must not sit on Dropbox, OneDrive, SharePoint, Google Drive, iCloud, kDrive or ownCloud. These services do not handle database synchronisation, the vendor flags a risk of corruption and declines all liability in case of loss. A Crésus folder placed in a synchronised space is an incident waiting for its hour, and the day's backup may already contain the damage.

Three families of access remain: the local workstation, the network share without a synchronisation agent, and the remote desktop. The question of storage on a NAS comes up often among French-speaking Swiss SMEs, and it deserves to be treated for what it is: a matter of access route and file locking more than of software. What counts is that no synchronisation agent watches the folder and that the network link is sized for per-file access.

Crésus Cloud offers the other route, a virtual desktop hosted at Silicom on servers in Switzerland, with daily backups on redundant servers in Lausanne and at a remote site in Switzerland, and two-factor authentication as an option. The software runs there remotely, which moves the storage question without removing it.

The company's own backup remains a separate undertaking, whichever route is chosen. It is framed on the record-keeping requirements for retaining documents, it is tested by a real restoration rather than by a green light, and it aims at a retention that covers the financial year, not only the past week. A copy that follows the corrupted file protects nothing.

A single employee writes in a client file, and the organisation has to bend to it

The most structuring lock in Crésus fits in one sentence. A single employee can modify a client file at a time, be it accounting, payroll or invoicing, the others accessing it read-only. Simultaneous work assumes additional licences and stays bounded by this per-file lock. It persists in Crésus Cloud, charged 26 francs per month before tax and per simultaneous access, since the Cloud publishes the desktop software remotely.

In practice this is managed through agreed entry windows rather than tacit habits. One person keeps the accounts, another prepares the invoices, and everyone knows who enters the client file and when. Additional licences are offered at half price and read-only licences exist for profiles that only need to read, which allows opening access to the figures without handing write rights to the whole team.

Sizing is prepared the same way. Crésus Salaires counts in brackets of 5 salaries, with a ceiling of 500 salaries per licence, and each additional bracket costs 150 francs before tax at purchase, 30 francs per year in Crésus+, or 5 francs per month in rental. A company that hires seasonally does better to look at this counter before the high season than in the middle of preparing payroll.

Three set-ups that hold over time

First set-up, the single workstation kept clean. One workstation writes, the files live on its disk or on a network share without a synchronisation agent, and the backup goes to a medium nobody else touches. Exchanges with the fiduciary go through export templates, and the Crésus+ subscription opens Synchro and FiduSync on the accountant's side. It is the cheapest and the most predictable formula for a structure of a few people.

Second set-up, the remote desktop on the company's server. Crésus runs on Windows Server, employees open a remote session, and the files never leave the server. Access from outside goes through a private channel, read-only licences serve the profiles that read, and the backup is organised at server level, with a retention designed for the legal retention of documents.

Third set-up, Crésus Cloud. The company takes simultaneous accesses at 26 francs per month before tax, hosting and backups are provided at Silicom in Switzerland, and the fleet of machines becomes ordinary again since the software runs elsewhere. The per-client-file write lock stays identical, two-factor authentication is switched on as an option, and the real decision concerns the number of simultaneous accesses really needed at peak times.

In all three cases, traffic with the rest of the tools rests on the same building blocks: fixed and documented import and export templates, the ISO 20022 formats for the bank, the QR-bill and eBill for customers. A set-up holds over time when the discipline covers three points: the path of the files, the direction of travel of each piece of data, and the named person who answers when an import stops along the way.

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.

• Crésus, official price listRental and purchase prices per module, as of 12.12.2025, VAT 8.1 % applicable
• Crésus CloudCHF 26.00 per month before tax and per simultaneous access, virtual desktop, Silicom hosting in Switzerland, daily backups in Lausanne and at a remote site, 2FA optional
• Crésus and synchronisation servicesOfficial vendor answer on Dropbox, OneDrive, SharePoint, Google Drive, iCloud, kDrive and ownCloud, risk of data corruption
• Crésus Facturation, specificationsPlatforms Windows, macOS, Linux, Cloud and Windows Server, single user for writing, multi-client capability, multilingual and multi-currency options
• Crésus Salaires, specificationsBrackets of 5 salaries up to 500 per licence, salary certificates, absences, bank payments, Logib export
• eBill sending from Crésus FacturationSending via the SIX network, 20 centimes per dispatch, active QR-IBAN, commercial register entry, issuing contract, registration fee CHF 20
• Swissdec register of certified softwareCrésus Salaires, Epsitec SA, Swissdec certified basic, ELM 5.0 with self-validated versions 5.1 and 5.3, cert. No. 1034.23
• Epsitec SA, eBill network partner of SIXRegistration of Epsitec SA as an eBill network partner for issuing invoices
• Crésus support and documentationImport and export templates, text and CSV formats, ISO 20022 pain.001, pain.002, camt.053 and camt.054, PostFinance API channel, EBICS, tilbago API key
• Directory of Crésus referencesResellers and IT specialists, fiduciaries using Crésus, training institutes

SURVEY OF 23.08.2026

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