EUDI Wallets Enable Automated Tax Filing with Pre-Filled Forms

Tax authorities integrate with EUDI Wallets for automatic tax filing with pre-filled income and deduction data.

How Income Credentials Transform Tax Filing

The fundamental innovation that EUDI Wallets bring to tax filing is the concept of verifiable income credentials. In the traditional tax system, income information flows through multiple disconnected channels: employers report wages to tax authorities through annual filings, banks report interest income separately, and citizens must reconcile all these sources in their personal tax returns. Discrepancies between what citizens report and what employers and banks report trigger audits, creating friction for both taxpayers and tax administrations.

With EUDI Wallet-based income credentials, this fragmented process becomes smooth. When an employer processes payroll, they simultaneously issue a verifiable income credential to the employee's EUDI Wallet. This credential contains the gross salary, tax withheld, social security contributions, and any benefits in kind, all cryptographically signed by the employer. Banks issue similar credentials for interest income and dividend payments. Social security agencies issue credentials for unemployment benefits, child allowances, and pension payments. Each credential is individually verifiable and tamper-proof.

When tax filing season arrives, the citizen opens their tax authority's portal and authenticates using their EUDI Wallet. The tax authority sends a credential request specifying the types of income credentials it needs. The citizen reviews the request in their wallet and authorizes the disclosure. The tax system receives the verified income data and automatically populates the tax return. Because the data comes from cryptographically signed credentials issued by the original sources (employers, banks, government agencies), the tax authority has high confidence in the data's accuracy, reducing the need for manual verification and auditing.

This system also catches errors before they cause problems. If an employer issues an incorrect income credential, the employee can flag the discrepancy in their wallet before submitting their tax return, initiating a correction process that resolves the error at the source rather than through a post-filing audit. This proactive error detection is expected to significantly reduce the millions of tax correction procedures that European tax authorities process annually, saving administrative resources on both sides.

Pre-Filled Tax Returns: The Nordic Model Goes European

The concept of pre-filled tax returns is not new. Nordic countries have been pioneers in this approach for decades. In Denmark, the SKAT tax authority pre-fills approximately 95% of personal tax returns with data from employers, banks, and other reporting entities. Swedish citizens receive a pre-completed tax return that they can approve with a single text message. Estonia's e-Tax system similarly pre-populates returns and allows citizens to review and submit them in minutes. These systems demonstrate that pre-filled tax filing is not only feasible but vastly preferred by citizens.

However, existing pre-filled tax systems rely on backend data sharing between tax authorities and reporting entities, which creates several limitations. The data flows through government infrastructure, raising sovereignty and privacy concerns when applied across borders. The data is only as current as the last reporting cycle, which may be months out of date. And citizens have limited visibility into and control over how their income data is collected and shared between institutions.

EUDI Wallet-based pre-filling addresses these limitations by putting the citizen at the center of the data flow. Instead of income data being shared directly between employers and tax authorities through backend channels, it flows through the citizen's wallet, giving them full visibility and control. The citizen can see exactly what data each party holds, verify its accuracy, and explicitly consent to sharing it with the tax authority. This citizen-mediated data flow is not only more privacy-respecting but also more legally defensible under GDPR, as the citizen provides explicit informed consent for each data sharing action.

The OECD has recognized this model as a potential best practice for digital tax administration. In its Tax Administration 2023 report, the OECD highlighted the potential of verifiable credentials and digital wallets to improve tax compliance, reduce filing burdens, and enhance taxpayer trust. The report noted that countries implementing wallet-based pre-filling could see compliance rates increase by 5-10 percentage points while simultaneously reducing administrative costs, representing a rare win-win in tax policy.

Cross-Border Tax Obligations and Mobile Workers

Cross-border taxation is one of the most complex and error-prone areas of European tax administration. An estimated 17 million EU citizens live or work in a member state different from their country of nationality, and many more have cross-border income from investments, rental properties, or remote work. These citizens often face dual filing obligations, meaning they must submit tax returns in two or more jurisdictions, each with different rules, forms, deadlines, and authentication requirements.

The EUDI Wallet dramatically simplifies this situation. A German citizen working in the Netherlands, for example, receives income credentials from their Dutch employer in their EUDI Wallet. When filing their German tax return (as required for their worldwide income), they can share these Dutch income credentials with the German Finanzamt, which receives cryptographically verified data about the income earned and tax paid in the Netherlands. The German tax authority can then accurately calculate the German tax obligation, apply double taxation treaty provisions, and credit the Dutch tax paid, all based on verified rather than self-reported data.

For the growing population of digital nomads and remote workers who may work from multiple EU countries in a single tax year, the wallet provides even more value. Income credentials accumulate in the wallet from multiple employers and clients across different jurisdictions, creating a complete and verified record of income and tax payments. When filing in any jurisdiction, the worker can selectively share the relevant credentials, providing tax authorities with exactly the information they need without requiring the worker to manually compile and translate documents from multiple countries.

The European Commission's proposal for a Directive on tax transparency and administrative cooperation (DAC8 and beyond) is expected to reference EUDI Wallet credentials as a mechanism for cross-border tax information exchange. This regulatory alignment between the tax and digital identity frameworks creates a foundation for a more integrated European approach to cross-border taxation, potentially simplifying obligations for mobile workers while improving tax collection efficiency for member states.

Freelancer and Self-Employed Use Cases

While employed workers benefit from employer-issued income credentials, freelancers and self-employed individuals face a more complex tax filing environment that the EUDI Wallet can significantly improve. Self-employed workers in the EU often deal with quarterly VAT filings, annual income tax returns, social security contributions in potentially multiple jurisdictions, and the administrative burden of managing invoices, receipts, and expense documentation.

The EUDI Wallet enables several innovations for self-employed tax administration. Clients can issue payment credentials to freelancers confirming the amount paid and the services rendered, creating a verified income trail. Platform economy operators like Upwork, Fiverr, and local equivalents can issue annual income summary credentials to their workers, mirroring what employers do for traditional employees. These credentials give freelancers and tax authorities a clear, verified picture of income from multiple sources without requiring manual compilation.

Expense management also benefits from wallet integration. Business expenses can be captured as verifiable credentials from merchants and service providers: a hotel stay generates an accommodation receipt credential, a software subscription generates a service credential, and a fuel purchase generates a transport expense credential. When filing their tax return, the self-employed worker can present these expense credentials alongside their income credentials, creating a complete and verified picture of their business finances that the tax authority can process with minimal manual review.

The qualified electronic signature capability of the EUDI Wallet is particularly valuable for self-employed workers. Invoices signed with a qualified electronic signature are legally valid across the EU, eliminating the need for paper invoices or jurisdiction-specific e-invoicing solutions. Tax documents, VAT returns, and social security forms can all be signed with the wallet, creating a streamlined administrative experience that was previously available only to larger businesses with dedicated accounting departments.

Digital Signatures for Tax Documents and Legal Validity

The integration of qualified electronic signatures into the EUDI Wallet resolves a longstanding pain point in European tax administration. Many member states require taxpayers to sign their tax returns, historically with a wet signature on a paper form and more recently with various national digital signature solutions. These national solutions are often incompatible across borders, meaning a French citizen filing taxes in Germany cannot use their French digital signature for the German tax return without additional steps.

Under eIDAS 2.0, qualified electronic signatures created through EUDI Wallets have the highest level of legal assurance and are recognized across all EU member states with the same legal effect as handwritten signatures. This means a qualified electronic signature from a Spanish EUDI Wallet is legally valid when applied to a Belgian tax return, resolving the cross-border signature recognition problem that has plagued European digital tax administration.

The technical implementation uses the wallet's secure element to store the signing keys, ensuring that the signature can only be created by the authorized wallet holder. The signing process typically involves biometric authentication on the device, confirming the signer's identity with high assurance. The resulting signature includes a timestamp, the signer's verified identity attributes, and a cryptographic proof that binds the signature to the specific document, preventing any post-signature modification.

For tax authorities, the move to wallet-based qualified electronic signatures eliminates the administrative burden of managing national digital certificate infrastructure. Many tax authorities currently operate their own certificate authorities or contract with national providers, creating significant ongoing costs. With EUDI Wallet-based signatures, the trust infrastructure is shared across the entire European ecosystem, reducing costs while improving interoperability. Tax authorities simply need to verify signatures against the EU trust registry rather than maintaining bilateral trust relationships with multiple national certificate providers.

Impact on Tax Compliance and Revenue Collection

The automation of tax filing through EUDI Wallets is expected to have a measurable impact on tax compliance across the EU. Tax compliance in Europe varies significantly between member states, with the VAT gap alone estimated at over 60 billion euros annually by the European Commission. While EUDI Wallet integration primarily addresses income tax filing rather than VAT collection, the principles of verified data and simplified filing apply broadly.

Research from Nordic countries demonstrates the compliance benefits of pre-filled tax returns. When Denmark transitioned to fully pre-filled tax returns, voluntary compliance rates increased significantly, as the barrier to accurate filing was reduced to reviewing and approving pre-populated data rather than manually gathering and entering information. Errors decreased proportionally, as the pre-filled data came from verified sources rather than taxpayer recollection. Similar outcomes have been observed in Estonia, Finland, and Sweden.

For tax administrations, the shift to verified credential-based filing enables a risk-based audit approach. Rather than random or broad auditing, tax authorities can focus audit resources on returns where citizen-provided data diverges from verified credential data, or where credential coverage is incomplete (suggesting unreported income). This targeted approach is more effective at detecting genuine non-compliance while reducing the burden of audits on compliant taxpayers.

The acceleration of refund processing is another significant benefit. Currently, tax refunds in many EU member states take weeks or months as authorities verify the information in submitted returns. With verified income and deduction credentials, the verification step is largely automated, enabling faster refund processing. Some tax authorities participating in pilot programs have reported potential refund processing time reductions from weeks to days, directly improving the financial wellbeing of citizens who depend on timely refunds.