Accounting for startups in Europe: entity, VAT, invoicing, e-invoicing

A startup in Europe needs three things from its accounting before it needs anything clever: a legal entity in one country whose rules it can actually follow, a VAT registration that matches what it sells and to whom, and invoices that are valid in the buyer's country — which from 2026 increasingly means structured e-invoices, not PDFs. Bookkeeping software keeps the record; a tax adviser files the returns. This page walks through those decisions for Germany, France, Belgium and Poland and says where a professional has to decide.

Choosing the entity country: where you operate, not where the form is easiest

The country of incorporation should be the country where the founders sit and the company is managed, because tax residence and social security follow management and people, not the registration certificate. A German team that incorporates elsewhere to save a fee generally ends up with a German permanent establishment and two sets of obligations instead of one.

Within that constraint, the four countries KRONENWERK serves in Europe differ in ways that matter to a small company:

Formation costs, notary requirements, minimum capital and the corporate tax rate are outside this page and change; take them from the national authority and confirm with a professional. What the table shows is that the accounting rules — language, currency, invoice format — are set by the country, and your software has to follow that country, not the other way round. The country overview lists what KRONENWERK does per country.

Registering for VAT: national authorities only, one number per country

You register for VAT with the national tax administration of the country where you are established, and you get a VAT identification number that starts with that country's code. Nobody else can issue one — the Commission warns that "only tax administrations have the right to issue a VAT number".

According to the Commission's summary, a VAT number is needed by a business that "carries out the supply of goods or services taxed with VAT; makes an intra-EU acquisition of goods; receives services for which it is liable to pay VAT" or supplies services for which the customer is liable. In practice a startup that sells to other businesses across borders needs the number from day one, because the reverse charge on cross-border B2B services only works when both parties have one.

Small-business exemptions exist in every country and change often — whether to use one is a decision for a professional, because it also removes the right to deduct input VAT. Selling digital services to consumers in other EU countries adds a second question: the One Stop Shop, an optional scheme under which VAT for all member states is declared in one quarterly return, with an annual EUR 10,000 threshold below which a supplier may keep applying its own country's rules. The SaaS-specific version of that question is on accounting for SaaS companies.

Invoicing rules: an EU core, national details on top

EU law sets a common minimum for what a VAT invoice contains; each country adds detail. The Commission puts it this way: businesses "are subject to a single set of basic EU-wide VAT invoicing rules and, in certain areas, national rules set by the individual Member State".

The EU core for a full invoice: date of issue, a unique sequential number, the supplier's and customer's names and addresses, the customer's VAT number where the customer is liable, a description, quantity and unit price of what was supplied, the VAT rate and amount with a breakdown by rate, and the date of supply if it differs from the invoice date. Special cases carry a wording, for instance "reverse charge". A credit note must reference the original invoice. Simplified invoices with fewer fields are allowed within national limits.

The national layer is what trips up a startup that used a generic template:

• Germany — the mandatory fields of § 14 UStG, the Kleinunternehmer wording where applicable, and retention obligations under the GoBD.
• France — SIREN/SIRET, the RCS mention, legal form and capital on the invoice, penalty and recovery-fee clauses, and specific exemption wordings.
• Belgium — enterprise number (KBO/BCE) as the VAT number, and since 2026 the structured format itself is a legal requirement in B2B.
• Poland — NIP of both parties, invoices in the KSeF schema once mandatory, and the KSeF number as the proof of issuance.

Electronic invoices are equivalent to paper under EU rules, and storage is largely free in form — "businesses are generally free to store invoices where and how they like" — but the retention period, the place of storage and the format that a tax audit will accept are national and require professional confirmation.

E-invoicing mandates: what applies now and what is scheduled

Belgium already requires structured B2B e-invoices; Germany, France and Poland are in the middle of phased mandates. A startup founded in 2026 should assume that PDFs will stop being enough within its first two years and choose invoicing software accordingly.

Belgium

"Business-to-Business (B2B) eInvoicing will become mandatory in Belgium from 1 January 2026", based on the law of 6 February 2024; the format is Peppol BIS Billing 3.0 and Peppol is "the primary format and transmission method". Details on the Belgium hub.

Germany

Every business has had to be able to receive e-invoices since 1 January 2025. On issuing, the Commission's country sheet states: "By January 1, 2027, businesses with a turnover exceeding EUR 800,000 will no longer be allowed to issue paper invoices or use unstructured electronic formats", and "by January 1, 2028, this requirement will extend to all businesses". Formats are XRechnung and ZUGFeRD. See the Germany hub.

France

From 1 September 2026 all companies must be able to receive e-invoices, and large and intermediate-sized companies must issue them; from 1 September 2027 small and micro companies must issue e-invoices and transmit e-reporting data. Invoices pass through approved platforms (plateformes agréées), described by the ministry as an "obligatory intermediary between businesses". See the France hub.

Poland

The Ministry of Finance's schedule for KSeF 2.0: launch on 1 February 2026, "mandatory for all entrepreneurs" from 1 April 2026 except the smallest (sales up to PLN 10,000 a month), and mandatory for those from 1 January 2027. See the Poland hub.

The complete schedule, with the thresholds that decide which wave a company is in, is kept on the mandate timeline. Which wave applies to your company depends on its turnover and size classification and requires professional confirmation.

Bookkeeping versus tax filing: two jobs, two responsibilities

Bookkeeping records what happened: every invoice, bill, bank movement and journal entry, in a ledger that balances. Tax filing turns that record into returns — VAT advance returns, the annual accounts, corporate tax — and submits them to the authority. Software does the first well; a qualified professional is responsible for the second, and in several countries certain filings can only be made through one.

A startup should expect its accountant to want three things from the software: a complete, unchangeable audit trail (issued invoices cannot be silently edited; corrections are credit notes), exports the accountant's own tools accept, and a clear VAT treatment on every document so the return can be built without re-deciding each line. What the accountant does not need is a second bookkeeping system that duplicates yours — agree early who posts what, and where the ledger of record lives.

When to involve an accountant

Before the first invoice, and again before the first cross-border sale, the first employee and the first fundraising round. Each of those creates obligations that are cheaper to set up correctly than to repair.

1. At formation — choice of legal form, VAT registration, small-business exemption, the chart of accounts, the fiscal year.
2. Before selling abroad — reverse charge versus OSS, evidence of customer location, whether a foreign registration is triggered.
3. Before hiring — payroll is a separate discipline with its own filings in every country on this page.
4. Before investors — share capital movements, convertible instruments and the annual accounts they will read.
5. Every filing period — VAT returns and the annual close. Software prepares; a professional files.

How KRONENWERK handles this

KRONENWERK is the bookkeeping side of that division of labour for companies in Germany, France, Belgium, Poland (limited), Canada and the United States. SUPPORTED WITH LIMITATIONS

• Country-correct invoices. Invoices, quotes and credit notes with the national mandatory fields, generated as structured e-invoices at issuance: XRechnung and ZUGFeRD for Germany, Factur-X for France, Peppol BIS Billing 3.0 UBL for Belgium, FA(3) XML for Poland; PDF with national tax rules for Canada and the US.
• A tax verdict per invoice from seller country, buyer country, business or consumer and kind of supply — including reverse charge and "requires professional confirmation" where a rule is not decidable from the facts. Buyer VAT IDs are checked against VIES at issuance.
• Double-entry ledger, bills and expenses, bank feeds (Enable Banking for European banks, Plaid for Canadian and US banks), multi-company, multi-currency, interface in EN, DE, FR, NL and PL.
• Transport. Peppol sending and receiving through an accredited access point provider (Storecove) once the company is connected in Settings → Delivery. French transmission through an approved platform is not yet production-ready (NOT YET READY). The KSeF module has not been used against the production system and KRONENWERK does not currently sell subscriptions to Polish companies.

Once a second entity or a second currency appears, read several companies, several currencies. If you are weighing a US-first tool, the checklist on what a European business needs is the place to start.