A fintech that sells to small businesses in Europe connects to national ledgers, one country at a time. A German customer's books sit in DATEV or Lexware Office, a French one's in Pennylane or Sage 100, a Dutch one's in Exact Online or Twinfield. Planning accounting integrations for European fintechs therefore starts with a list of countries and the ledgers used in each. Among unified APIs, Chift, a Belgian provider, has the deepest coverage of French and Belgian ledgers, including on-premise ones through a local agent. Apideck covers Exact Online and many Benelux and Nordic cloud ledgers, has connectors Chift doesn't list, such as banqUP and Visma Netvisor, and offers HR and CRM APIs from the same provider. Neither covers the Italian or Polish market leaders yet.
Disclosure: Apideck publishes this guide and competes with Chift and Codat. Connector statuses come from each provider's own pages and docs, read on 5 November 2026, and they change often.
Europe is a set of national ledger markets
Accounting software follows national tax and bookkeeping law, so each country grew its own leaders. The Apideck Europe accounting integration map shows the spread by country, and the post on multi-country accounting integration explains why even global brands such as Exact Online and Sage behave like separate products per country. The EU has more than 23 million SMEs, and the question for a fintech is which of their ledgers it can reach, with what effort, and under which data rules.
The table summarises the main systems per market and Apideck's status for each, taken from its integration pages and developer docs on 5 November 2026.
| Country | Systems to check | Apideck status (5 Nov 2026) | Chift status (5 Nov 2026) |
|---|---|---|---|
| Germany | DATEV, Lexware Office, sevDesk | DATEV Unternehmen Online, Lexware Office and sevDesk supported, DATEV itself on the radar | DATEV, DATEV Buchungsdatenservice, Lexoffice and sevDesk supported |
| France | Pennylane, Cegid Loop, Sage 100 and Sage 50, MyUnisoft | Pennylane supported, the rest on the radar | Pennylane, Cegid Loop, Sage 100 FR, Sage 50 FR and MyUnisoft supported |
| Netherlands | Exact Online, Twinfield, Yuki, SnelStart, Moneybird | Exact Online, Twinfield, Yuki, SnelStart and Moneybird supported | Exact Online, Twinfield, Yuki, SnelStart, Moneybird and Nmbrs Accounting (Yuki's new Dutch name) supported |
| Belgium | Exact Online, Winbooks, Octopus, banqUP, Yuki | Exact Online, banqUP and Yuki supported, Winbooks and Octopus on the radar | Exact Online BE, Winbooks Classic, Octopus, Yuki and Sage BOB 50 supported |
| Nordics | Fortnox, Visma, Tripletex, Fiken, e-conomic, Procountor, Netvisor | Procountor, Visma Netvisor, Fortnox, Spiris, Fiken and e-conomic supported, Tripletex in development | Spiris, Dinero, Fortnox, Tripletex, Fiken, e-conomic and Procountor supported; Visma eAccounting supported but listed for the Netherlands |
| Spain | Holded, a3, Sage 200 | Holded supported, a3innuva and Sage 200 Spain on the radar | Holded, a3ERP and Sage 200 ES supported |
| Italy | TeamSystem, Fatture in Cloud | On the radar | No TeamSystem accounting connector; Fatture in Cloud in its invoicing API |
Chift's column comes from the coverage file its accounting docs load. Codat's accounting integrations list covers Exact but has no DATEV, Pennylane or Sage 50 France.
Germany: DATEV runs through the tax advisor
DATEV is a cooperative of tax advisors. It ended 2025 with about 927,900 customers, and in March 2026 it counted more than 750,000 users of DATEV Unternehmen online, its cloud platform for exchanging documents between businesses and their advisors, according to its March 2026 results. Because tax advisors sit between DATEV and the business, access runs through DATEV's own approval. Its developer portal splits the APIs into separate products, and every app has to book a technical review before it goes live. Authentication is DATEV's own version of the OpenID Connect authorization code flow with PKCE. A listing on the DATEV Marketplace as an interface partner needs a data service that at least 25 customers use, per DATEV's FAQ for software vendors.
The smaller cloud tools are simpler. Lexware Office, formerly lexoffice, offers a public API with a private API key from its XL plan upward. sevDesk authenticates with one API token per administrator, as its OpenAPI spec describes.
France: Pennylane, Cegid and an on-premise Sage base
Pennylane gives OAuth only to partners its partnerships team has validated: "Before using OAuth, register your app with Pennylane by contacting our Partnerships team," says its OAuth walkthrough. Cegid Loop secures its APIs with an API key that the accounting practice's administrator generates, plus a subscription key from Cegid. Sage 100 runs on the customer's premises; Sage's own developer site documents a Sage 100 connector for Microsoft 365 through Power Automate and Power Apps, which needs extra setup steps on Sage's hosted version.
Apideck supports Pennylane and has Cegid Loop, Sage 50 and Sage 100, MyUnisoft and EBP on its radar. Chift supports Pennylane, Cegid Loop and MyUnisoft, and reaches Sage 100 FR and Sage 50 FR through an agent installed on the customer's machine. For a fintech whose customers are mostly French, Chift has the wider coverage today.
France's e-invoicing reform is already under way. Every company has had to be able to receive e-invoices since 1 September 2026, large and mid-size companies issue them from the same date, and small and micro companies from 1 September 2027, per the Ministry of the Economy.
Netherlands and Belgium: Exact Online and a long tail
Exact Online appears on both countries' lists. Exact's developer page promises access to "675.000+ bedrijven" and in the Netherlands charges EUR 15 a month for the developer subscription you need to connect several customers, with OAuth 2.0. Each country runs its own Exact instance, which the multi-country post covers.
Below Exact the access rules vary a lot. Twinfield, from Wolters Kluwer, uses SOAP web services with OpenID Connect. Yuki uses SOAP with an API key, free up to 1,000 calls a day per domain, according to its API documentation. SnelStart is the most selective of these: its API page says it is "terughoudend" (reluctant) to admit new production integrations, judges each request separately, and wants at least five named customers at application. In Belgium, WinBooks Accounting Classic is a desktop product that integrates through files or a local DLL, while WinBooks on Web has a REST API, per the WinBooks developer docs. Octopus offers its API for free and issues a software-house ID by email, per its API manual.
Apideck supports Exact Online, banqUP, Odoo, Twinfield, Yuki, SnelStart, Moneybird and e-Boekhouden.nl. Winbooks, Octopus and Sage BOB are on its radar. Chift also supports Twinfield, Yuki and SnelStart, plus Winbooks Classic, Octopus and Sage BOB 50, so Belgium's local accounting software is better covered there.
Belgium has required structured e-invoices over Peppol between VAT-registered companies since 1 January 2026. E-reporting is planned for 2028 but still has to be written into Belgian law, says the FPS Finance FAQ. The Dutch government announced on 11 September 2026 that it wants domestic B2B e-invoicing from 1 July 2030 and reporting from 1 July 2031; the bill is expected before summer 2027.
Nordics: five integration stacks
The Apideck post on Nordic accounting software covers Sweden, Norway, Denmark and Finland in detail. For planning purposes, Fortnox reported 612,000 subscription customers in its Q1 2025 report, and Fiken requires OAuth2 for third parties acting for customers. Apideck supports Procountor and Visma Netvisor in Finland, plus Fortnox, Spiris, Visma eAccounting, Fiken and e-conomic. Tripletex is in development, and PowerOffice Go, Dinero, Billy and Uniconta are on its radar. Chift is ahead on Tripletex and Dinero. Both support Spiris and Visma eAccounting, though Chift's file gives the Netherlands as Visma eAccounting's country. Apideck is ahead on Visma Netvisor, which Chift's file doesn't list.
Spain, Italy and Poland
Visma bought Holded, a Spanish cloud ERP, in 2021; its API uses a bearer API key. Apideck supports Holded. Chift supports Holded and reaches a3ERP through its local agent, while a3innuva and Sage 200 Spain are on Apideck's radar.
Spain's B2B e-invoicing obligation starts on 6 October 2027 for businesses with turnover above EUR 8 million and on 6 October 2028 for the rest, per the tax agency's calendar. The VERI*FACTU rules for invoicing software still carry dates of 1 January and 1 July 2027 in the consolidated decree. The Ministry of Finance announced on 5 October 2026 that it would move them to October 2028, but on 5 November that change was not yet in the consolidated text in the official journal.
Italy has required invoices between businesses established there to go through the SDI exchange system since 1 January 2019, per the Agenzia delle Entrate. TeamSystem reported 3.1 million customers for 2025 in its results release, and Fatture in Cloud, which TeamSystem owns, offers self-service OAuth apps. Neither Apideck nor Chift has an accounting connector for TeamSystem, and Fatture in Cloud is on Apideck's radar.
In Poland, KSeF has been mandatory for receiving invoices since 1 February 2026, with issuing phased in on 1 February and 1 April 2026 and the smallest issuers, up to PLN 10,000 of invoices a month, exempt until the end of 2026, per the KSeF portal. Comarch, Symfonia and InsERT are on Apideck's radar, and Chift's accounting file has no Polish connector.
E-invoicing changes the data you read and write
Germany has required every business to be able to receive e-invoices since 1 January 2025, according to the Finance Ministry FAQ. Under § 27 UStG, businesses with prior-year turnover above EUR 800,000 issue them from 2027, and the rest by 2028. At EU level, ViDA brings digital reporting for cross-border B2B sales from 1 July 2030.
For a fintech, the mandates matter because they change what sits in the ledger. Invoices carry VAT categories and buyer identifiers in fixed formats, and the network adds references and statuses, such as the KSeF number or the French invoice status. An expense, lending or payments product that reads invoices will meet those fields first, before it has to send anything. The Apideck guide on e-invoicing APIs in Europe lists what each mandate needs from the ledger, country by country. A unified accounting API reads and writes the invoices; the sending itself stays with a certified provider in each country.
Data residency, GDPR and DORA
Ledgers hold personal data, from customer contacts to employee expenses, so an integration provider that handles it is a processor or sub-processor, and GDPR Article 28 requires a contract that binds it. If any of that data leaves the EU, the transfer rules of Chapter V apply, and the European Data Protection Board says remote access from a third country to data stored in the EU counts as a transfer. Transfers to US companies certified under the EU-US Data Privacy Framework need no extra safeguards; the EU General Court upheld that framework on 3 September 2025, and an appeal is pending at the Court of Justice.
Regulated fintechs also fall under DORA, which has applied since 17 January 2025. It requires a register of all ICT third-party arrangements, and each contract has to state the regions or countries where data is processed and stored, under Article 30 of Regulation (EU) 2022/2554. An integration provider is one of those arrangements, so ask for its hosting region and storage model in writing.
Chift and Apideck give different answers. Chift says on its security page that data is hosted in the EU with no transfers outside the union, and that it is ISO 27001 certified. Its caching docs say it caches retrieved data for up to five minutes, and an opt-in data layer serves reads from a copy it keeps. Apideck's zero data retention page describes a pass-through design: customer records are processed in memory, not stored, and hosting is in the EU by default. OAuth tokens are stored encrypted, optional API logs keep request metadata, and QuickBooks Desktop, an on-premise product, is the stated exception where data may be held temporarily during a sync.
Checks before you choose a provider
- List your customers' ledgers by country and by revenue, then check each provider's own coverage page for those exact systems.
- Read each vendor's access rules early. DATEV and SnelStart, for example, review integrations themselves, and their timelines become your timeline.
- Check on-premise systems separately. Sage 100 and WinBooks Classic, for example, need software on the customer's machine or a file exchange.
- Test the objects you write, such as invoices and journal entries, on the ledgers that matter most, and plan for asynchronous writes where a vendor queues them.
- Ask where data is processed and stored, caches included, and get it into the contract for your DORA register.
- Map the e-invoicing fields your product reads in each country before your customers' mandates start.
Choosing between Apideck and Chift
If your customers are mostly in France or you need Belgian desktop software, put Chift first on the list. If they are spread across the Netherlands, the Nordics and markets outside Europe, and you also need HRIS or CRM data, Apideck's coverage of Exact Online, Procountor and Visma Netvisor, plus global platforms such as Xero and QuickBooks, fits that mix, with no copy of the data kept. Either way, start from your own customer list. To test the European ledgers Apideck supports today, start a trial of the Apideck Accounting API and connect your three most common ledgers first.
