Every entrepreneur in the Netherlands is legally required to retain invoices and administrative records. The Dutch Tax Authority (Belastingdienst) sets requirements for the duration, the format and the accessibility of that retention. For organisations transitioning to e-invoicing, these rules are particularly relevant, because they confirm that digital invoices must be stored digitally.

The standard retention period for invoices and basic records is 7 years. Certain categories require a longer period:

The retention period does not start on the invoice date but at the moment the data loses its current relevance. A 4-year lease contract, for example, is first part of the active administration for 4 years; only after that does the 7-year retention period begin.

Note: even after dissolving your business, the administration must be retained so the Tax Authority can carry out a final audit.

The Tax Authority is clear: invoices must be stored in the format in which they were sent or received. An invoice received digitally (as UBL, Peppol BIS or XML file) must be stored digitally. Printing it out and deleting the digital file is not permitted.

The reverse also applies: an invoice received on paper should in principle be kept on paper, unless you apply the conversion principle (see below).

Tip: when you send or receive invoices via eConnect, they are automatically archived digitally in the platform. This means you immediately comply with the Tax Authority's format requirement.

The conversion principle allows entrepreneurs to transfer data from one storage medium to another. Examples include scanning paper invoices to digital, copying files from a CD-ROM to a USB drive, or converting data to a different file format.

After a valid conversion, the original document no longer needs to be retained. The digital version takes the place of the original.

The Tax Authority sets four conditions for conversion:

1. Accurate and complete: the converted data must be identical in content to the original.
2. Available throughout the entire retention period: the data must remain accessible for the full 7 or 10 years.
3. Reproducible and readable: the data must be reproducible, readable and verifiable within a reasonable time.
4. Preserve authenticity features: when scanning paper documents, authenticity features must be stored alongside the content (colour, logo, watermark, paper type, signature). If this is not technically possible, they must be compensated with technical measures (high resolution) or organisational measures (reconciliation with bank statements).

Not all documents may be converted. The balance sheet, the profit and loss statement and certain customs documents must be retained in their original format.

The Auditfile Financieel is an extract of the general ledger and is supported by most accounting software. However, retaining only the audit file is not sufficient: all underlying detailed records (invoices, receipts, contracts) must remain available.

The Tax Authority considers all data relating to your business as part of the administration, regardless of format:

• Received invoices and copies of sent invoices
• Bank statements
• Contracts, agreements and correspondence
• Cash administration (including draft notes) and receipts
• Software and data files
• Financial records (purchase/sales journal, general ledger)
• Interim control calculations

Business messages via email, WhatsApp, SMS and social media also fall under the retention obligation. During an audit, these must be available in the format requested by the inspector. If no separation has been made between business and personal data, personal data must also be retained.

The retention obligation requires that digital files remain accessible throughout the entire retention period. In practice, this may mean you need to keep old hardware or software if files can only be read on them. When choosing an archiving solution, it is therefore advisable to work with open, widely supported formats.

Tip: structured e-invoices in UBL or Peppol BIS format are open standards that do not depend on specific software. This makes it easier to meet the long-term accessibility requirement compared to proprietary formats.

If your administration is maintained wholly or partly by a bookkeeper, accountant or other firm, the data held by that third party must also be retained in accordance with the same rules.

If your administration is incomplete or the retention period has been too short, the Tax Authority may determine your turnover and profit themselves. If you disagree with their calculation, the burden of proof falls on you. This is known as the reversal of the burden of proof and is a significant sanction you want to avoid.

The fiscal retention rules align seamlessly with the transition to e-invoicing:

• Digital invoices are equivalent to paper invoices according to the Tax Authority, provided authenticity, integrity and readability are guaranteed.
• Retaining in original format means UBL and Peppol invoices are archived digitally. This happens automatically when you work via eConnect.
• The conversion principle offers a transition path: paper invoices may be scanned and stored digitally, after which the paper original is no longer needed. This lowers the threshold for working fully digitally.
• Open standards (UBL, Peppol BIS) guarantee long-term readability without dependency on specific software.

Want to know which data is required on an invoice? Read more about statutory invoice requirements.

• Statutory invoice requirements for e-invoices
• E-invoicing in the Netherlands: what is mandatory?
• What is Peppol and how does the network work?
• From semantics to syntax: how e-invoice standards work