ERP and accounting software for Denmark: moms, OIOUBL

Danish compliance in one view

Running the books of a Danish business means using a digital bookkeeping system that meets the 2022 Bookkeeping Act, charging 25% VAT and filing it half-yearly, quarterly or monthly, reporting pay to eIndkomst, keeping records for five years and filing an annual report in Danish or English with the Danish Business Authority. It matters because Denmark regulates the software itself, not only the filings.

Two authorities share the ground. Skattestyrelsen, the Danish Tax Agency, runs VAT, A-tax, the labour market contribution and eIndkomst through its online services. Erhvervsstyrelsen, the Danish Business Authority, owns the Bookkeeping Act and the Financial Statements Act, keeps the register of approved digital standard bookkeeping systems, receives annual reports and operates NemHandel, the national e-invoicing infrastructure.

This page sets out what those rules require as of September 2026, what they mean for an ERP, and how Skyline Nexus ERP fits a Danish business.

• Tax authority: Skattestyrelsen (Danish Tax Agency)
• Bookkeeping and annual reports: Erhvervsstyrelsen (Danish Business Authority)
• Currency: Danish krone; standard VAT rate 25%
• Digital bookkeeping: phased in from 1 July 2024 to 1 January 2026
• E-invoice formats: OIOUBL via NemHandel, and Peppol BIS

The digital bookkeeping requirement and its timeline

The Bookkeeping Act (Act No 700 of 24 May 2022) replaced a principles-based law with concrete requirements for the system a business keeps its books in. It distinguishes two routes. A registered digital standard bookkeeping system is one that its provider has notified to and registered with the Danish Business Authority, and the provider is responsible for it meeting the requirements. A non-registered system, such as one developed specially for the business or a foreign system not sold in Denmark, puts that responsibility on the business itself.

The obligation was phased in. Companies in accounting classes B, C and D that use a registered standard system must follow the digital bookkeeping rules for financial years beginning on or after 1 July 2024. The same companies using a non-registered system are covered for financial years beginning on or after 1 January 2025. Sole proprietorships, associations and other businesses outside the Financial Statements Act became subject to the duty from 1 January 2026 if their net turnover exceeded DKK 300,000 in two consecutive years; for those with a non-calendar financial year it starts with the 2026 financial year.

A foreign system that is marketed in Denmark counts as a standard system, and its provider must notify it for registration. The published register lists each approved system with its registration number and provider. A buyer can check that register before choosing, and should.

• Registered standard system, class B to D: financial years from 1 July 2024
• Non-registered system, class B to D: financial years from 1 January 2025
• Sole proprietorships above DKK 300,000 for two years: from 1 January 2026
• Foreign system marketed in Denmark: provider must register it

What the system itself must do

The Executive Order on non-registered systems (No 205 of 29 February 2024) is the clearest statement of the functional bar, because the business must meet it directly. Every transaction needs fields for the transaction date, amount, voucher number, text and, for foreign currency, the exchange rate at the transaction date. The system must stamp each recorded transaction with a registration date, a consecutive number or ID and the identity of the person or program that recorded it, and it must prevent users from changing, backdating or deleting recorded transactions; errors are corrected by new entries.

It must store the documentation for purchases and sales, showing the date, type of supply, amount, both parties with CVR or SE numbers, VAT and payment details. It must take a complete backup at least weekly to a server in an EU or EEA country, hosted by a party that is not related to the business. It must automatically send and receive e-invoices and credit notes via NemHandel in OIOUBL and in Peppol BIS, generate a SAF-T file in the format defined by the Danish Business Authority, and support reconciliation of the books with the bank account while clearly flagging unreconciled entries. Breaches are punishable by fine.

Registered standard systems meet a parallel list set out for their providers, including OIOUBL and Peppol exchange, bank reconciliation by CSV import, bank integration or PSD2, classification against a public standard chart of accounts, and daily incremental plus weekly full backups stored in the EU or EEA.

VAT: one rate, registration and filing

Danish VAT (moms) is 25% of the selling price, and Denmark does not use reduced rates the way most EU states do, which makes rate selection simpler than in the rest of the Nordic region. The complexity sits instead in exemptions, reverse charges and cross-border rules.

A business must register once its sales exceed DKK 50,000 in a 12-month period; below that, registration is optional. Once registered it must file a return for every period, even a nil return, through the Tax Agency's e-tax service for businesses.

The filing rhythm follows VAT-able turnover. Below DKK 5 million a business settles half-yearly, between DKK 5 million and DKK 50 million quarterly, and above DKK 50 million monthly; newly registered businesses start on quarterly settlement, and any business can ask for a shorter period. A quarter's return and payment fall due about two months and a day after the quarter ends, for example 1 September 2026 for the second quarter of 2026, which is also the deadline for half-yearly filers' first half of 2026, while monthly filers report around the 25th of the following month, such as 25 February 2026 for January. Late filing costs DKK 1,400 per period, plus interest.

E-invoicing: NemHandel, OIOUBL and what is not mandatory

Denmark was an early mover: since 2005 suppliers have had to invoice public authorities electronically through NemHandel, the shared infrastructure run by the Danish Business Authority. OIOUBL is the Danish adaptation of the OASIS UBL standard, and public authorities are registered in the NemHandel Registry, which acts as a central address lookup alongside the Peppol network.

For business-to-business trade the picture is subtler than a mandate. The Bookkeeping Act requires the bookkeeping system to be able to send and receive e-invoices in both OIOUBL and Peppol BIS, but as of September 2026 Danish law does not require every B2B invoice to be issued electronically. We are not going to invent a Danish B2B deadline that has not been announced. The EU's VAT in the Digital Age package will require e-invoices and digital reporting for cross-border B2B supplies from 1 July 2030.

For an ERP buyer the consequence is practical: in Denmark the ability to exchange OIOUBL and Peppol invoices is not a nice-to-have, it is part of what makes a bookkeeping system lawful.

Annual reports, audit exemption and record retention

Companies report under the Financial Statements Act in classes: class A for businesses without a reporting duty, class B for small companies, class C for medium and large companies and class D for listed and state-owned companies. Listed groups prepare consolidated accounts under EU-adopted IFRS. Annual reports must be filed in Danish or English. Class B and C companies must file within six months of the end of the financial year, and class D companies within four months.

A class B company can opt out of audit if, for two consecutive financial years, it does not exceed two of three limits on the balance sheet date: a balance sheet total of DKK 4 million, net revenue of DKK 8 million, and an average of 12 full-time employees. Class C and D companies must always be audited, and the Business Authority runs automatic checks on companies that opt out.

Accounting material must be stored securely for five years from the end of the financial year it relates to, protected against destruction, loss and falsification, and retrievable throughout. For a digital system that means five years of transactions, vouchers and the audit trail must survive, including a change of provider.

Payroll: eIndkomst, A-tax and AM-bidrag

When a Danish employer pays wages it withholds A-tax and the labour market contribution, AM-bidrag, which is 8% of AM-income, and reports each payment to eIndkomst, the national income register. Small and medium employers, defined as those with annual AM-bidrag under DKK 250,000 and A-tax under DKK 1 million, pay by the 10th of the following month. From 2026 employers do not report or pay AM-bidrag for young employees up to and including 31 December of the year they turn 17.

For the ledger the result is a payroll journal each pay run, and a monthly reconciliation of the A-tax and AM-bidrag liabilities to what was reported in eIndkomst and paid through the tax account.

Cities and regions: where the rules differ

Within Denmark proper the rules are national. A business in Copenhagen, Aarhus, Odense, Aalborg, Esbjerg, Randers, Kolding, Horsens, Vejle or Roskilde charges the same 25% VAT, files through the same e-tax service and falls under the same Bookkeeping Act. Municipal income tax rates differ, but that reaches the employer through each employee's tax data in the payroll process rather than through any regional return.

The real geographic line is the North Atlantic. The Faroe Islands and Greenland are not part of the Danish VAT area and lie outside the EU VAT area, so for VAT a sale of goods from Copenhagen to Tórshavn or Nuuk is treated like an export to a third country, without Danish VAT. A business trading with them needs separate tax codes and export documentation rather than intra-EU treatment.

How Skyline Nexus ERP handles Danish requirements

Skyline Nexus ERP is a cloud ERP with a double-entry general ledger under the Fiscal Authority menu, and its ledger follows the discipline the Bookkeeping Act describes. Journal entries must balance, each takes its number from a configurable sequence, and posted journals are never edited or deleted: they are reversed, which creates a mirror-image posted journal and marks the original reversed. When a sale is edited within the configured Transaction Edit Days, or deleted to the Recycle Bin, its journal is reversed rather than overwritten, so the ledger keeps both entries; a short Transaction Edit Days setting narrows that window further. The Accounting Audit Trail records who created, posted or reversed an entry, with old and new values, IP address and browser.

Treasury bank reconciliation imports statement files in CSV, TXT, XLSX or XLS, matches items, marks outstanding ones and shows the book balance against the statement balance, the kind of bank reconciliation the rules ask a system to support. With the auto-post switches on, which start off, sales, purchases, payments and expenses post balanced journals with VAT computed per line, the VAT Return screen prefills the figures for the Danish e-tax service, and fiscal periods can be soft-closed or locked.

OIOUBL and Peppol BIS exchange through NemHandel and the Danish SAF-T export are part of the national connectors being rolled out market by market: tell us your country and we will confirm your go-live date. Until they are live for your company, the working setup is to keep the statutory books in a registered Danish bookkeeping system and run Skyline Nexus ERP for operations such as stock, sales, projects and assets, transferring summaries to the statutory system or linking the two through a partner-led integration using the Skyline Nexus ERP Connector REST API. Danish payroll and eIndkomst reporting run in Danish payroll software or through a payroll partner, with the payroll journal posted to the ledger each month.

Rates, regimes and deadlines in this summary change, and many countries are actively legislating on e-invoicing. This is general information, not tax or legal advice — confirm the current position with the authority named above or with your tax adviser before you rely on it.