Key points
- Micro, small, and medium-sized entities have filed via SBR since 2016-2017. Large entities must file via SBR from financial year 2025.
- The auditor's report (controleverklaring) is tagged using the NBA's Verklaringen Taxonomie and digitally signed with the accountant's personal professional certificate.
- Block tagging of notes and the management report becomes mandatory from financial year 2026.
- An entity that files outside SBR when the mandate applies has not met its BW2 Article 394 publication obligation.
What is SBR?
Most Dutch audit teams first encounter SBR when a client that previously filed a PDF at the KVK suddenly needs to submit tagged XBRL data. The file should tell a story here: why the obligation triggered, what format was used, whether the tagged figures match the signed accounts, and who signed off on the consistency check. We've seen this on about half the engagements where a client crosses the large-entity threshold for the first time.
SBR (Standard Business Reporting) replaces paper and PDF filing with a structured data exchange built on XBRL. The entity's accounting software maps general ledger balances to elements in the Nederlandse Taxonomie, which defines every line item the KVK, the Belastingdienst, CBS, and participating banks accept. The tagged data travels through Digipoort (the government's secure messaging gateway) authenticated by a PKIoverheid certificate.
For annual accounts filed at the KVK under BW2 Title 9, two format options exist: a flat XBRL instance and an iXBRL Report Package. Large entities will typically use iXBRL because it preserves the human-readable layout while embedding machine-readable tags. From FY2025, the filing obligation extends to large legal entities (those exceeding the BW2 size thresholds for two consecutive years). From FY2026, block tagging of notes and the management report becomes mandatory, closing the gap between what's filed and what's machine-readable.
The auditor's involvement centres on NBA Alert 50, which specifies the work an external accountant must perform before granting written permission to reuse the controleverklaring in the SBR Report Package. The auditor verifies that the SBR version of the annual accounts is consistent with the signed FS and that the XBRL tagging doesn't misrepresent the underlying figures. The NBA's Verklaringen Taxonomie structures the audit opinion itself into tagged fields, and the accountant signs it digitally with a personal professional certificate issued by the NBA.
Worked example: Van der Berg Logistics B.V.
Client: Dutch transport and logistics company, FY2025, revenue EUR 19M, Dutch GAAP (RJ) reporter. Van der Berg exceeds the medium-size thresholds and qualifies as a large entity for the first time in FY2025 after two consecutive years above the limits.
Step 1: confirm SBR filing obligation
Van der Berg crossed the large-entity thresholds (balance sheet above EUR 25M, net turnover above EUR 50M, headcount above 250, and two consecutive years above the limits) for FY2023 and FY2024. BW2 Article 394 requires publication at the KVK. The Besluit elektronische deponering handelsregister mandates SBR filing for large entities from FY2025 onward.
Step 2: prepare the SBR report package
Van der Berg's finance team maps the FY2025 annual accounts to the Nederlandse Taxonomie using iXBRL-capable reporting software. The balance sheet and profit and loss account are tagged at element level, along with the cash flow statement. The notes are included as block-tagged HTML because element-level note tagging isn't yet required for FY2025.
Step 3: auditor review of the SBR report package
The engagement team reviews the iXBRL output against the signed annual accounts per NBA Alert 50. The team checks that revenue of EUR 19M, total assets of EUR 27M, net profit of EUR 1.1M, and the related-party note all match the tagged values. Two tagging discrepancies are identified: a EUR 0.3M provision classified under the wrong taxonomy element and a related-party disclosure omitted from the tagged notes. Both are corrected before filing.
Step 4: file through Digipoort
Van der Berg submits the corrected SBR Report Package through Digipoort using the entity's PKIoverheid certificate. The KVK returns a confirmation receipt. The annual accounts are published within the 8-day window required by BW2 Article 394(1) following adoption by the general meeting.
Van der Berg's first SBR filing as a large entity is defensible because the size classification is documented for two consecutive years, the tagging was reconciled to the signed accounts, discrepancies were corrected before submission, and the auditor's permission under NBA Alert 50 is on file.
Why it matters in practice
At firms like ours, the honest frustration is that teams treat the SBR filing as a tick box exercise performed after the audit is complete. Nobody goes back to verify that the tagged figures match the signed annual accounts. But NBA Alert 50 requires the auditor to perform specific procedures on the SBR Report Package before granting written permission to reuse the controleverklaring. Submitting a Report Package with tagging errors that contradict the audited figures creates a gap between the filed version and the opinion the auditor issued.
Firms also overlook the transition for large entities. An entity that exceeded the size thresholds for FY2023 and FY2024 must file via SBR for FY2025, even if prior filings were submitted as PDF. Missing this transition means the annual accounts aren't validly published under BW2 Article 394, which can trigger AFM follow-up for OOB entities or KVK enforcement for non-OOBs.
SBR vs. ESEF
| Dimension | SBR (Standard Business Reporting) | ESEF (European Single Electronic Format) |
|---|---|---|
| Scope | All Dutch legal entities required to file at the KVK (micro through large) | EU-listed issuers filing annual financial reports under the Transparency Directive |
| Taxonomy | Nederlandse Taxonomie (based on Dutch GAAP/RJ and IFRS where applicable) | ESEF taxonomy (based on IFRS Taxonomy, maintained by ESMA) |
| Filing destination | KVK via Digipoort | National competent authority (AFM in the Netherlands) via OAM |
| Governing law | BW2 Article 394 and Besluit elektronische deponering handelsregister | Regulation (EU) 2019/815 (ESEF RTS) |
| Audit involvement | NBA Alert 50 consistency check before reuse of controleverklaring | Auditor reports on whether the annual financial report complies with ESEF requirements |
The distinction matters on Dutch engagements where the client is both listed (ESEF applies) and a large legal entity (SBR applies). The two filings serve different regulators and use different taxonomies with different tagging requirements. An entity that assumes its ESEF filing satisfies the KVK obligation files incorrectly.
Related terms
Related reading
Frequently asked questions
Does the auditor need to audit the XBRL tags in an SBR filing?
The auditor does not audit the tags themselves. NBA Alert 50 requires the auditor to verify that the SBR Report Package is consistent with the signed annual accounts before granting permission to reuse the controleverklaring. This is a consistency check, not a separate assurance engagement on the tagging. If the auditor identifies material inconsistencies between the tagged data and the signed accounts, the auditor withholds permission until the entity corrects them.
What happens if a company files annual accounts outside SBR when the mandate applies?
The entity has not met its publication obligation under BW2 Article 394. The KVK may refuse the filing or flag it as incomplete. For statutory audit clients, the auditor should consider whether the failure to file in the prescribed format affects the other-information procedures under ISA 720.14, since the published version of the accounts may differ from the version the auditor examined.
When does block tagging of notes become mandatory?
Block tagging of notes, the management report, and other information becomes mandatory for financial years starting on or after 1 January 2026. For FY2025, notes may be included as untagged or block-tagged HTML within the iXBRL Report Package without element-level tagging.