The European Digital Identity Wallet as a Technical and Organisational Challenge

The EUDI Wallet is being introduced, and German municipalities will be required to support it. It is a mandatory component of public administration digitalisation. Citizens will use the EUDI Wallet mobile app to identify themselves, submit applications, provide credentials, and sign documents digitally. Municipalities must accept the wallet and, in certain cases, issue digital credentials for it themselves.

For municipal IT landscapes, this obligation comes at a time when budgets are as limited as the number of experts familiar with the topic. The central question is therefore not whether integration will happen, but how the EUDI Wallet can be integrated into existing government IT systems.

The Regulatory Context: Why Municipalities Must Act Now

With the eIDAS 2.0 regulation, the EU is establishing a unified legal framework for digital identities. A core component is the EUDI Wallet app, which will be available to all citizens. Public authorities have a clear mandate in this regard.

When Do the Requirements Apply? Acceptance and Issuance at a Glance

Acceptance Obligation

Public authorities must accept EUDI Wallets as soon as they become available to citizens. According to current planning, this is expected to happen toward the end of 2026. In practical terms, this means that from 2027, municipalities will need to integrate the EUDI Wallet for identification and attribute verification in administrative procedures.

Issuance / Issuer Role

There is no general obligation requiring every municipality to immediately issue all credentials as wallet certificates. However, if a public authority issues a credential digitally and it falls within the scope of eIDAS 2.0, it must be provided in a wallet-compatible format.

In addition, all these processes must meet the eIDAS “high” assurance level, including strong authentication, integrity, and verifiability. This affects not only large cities but every municipality, regardless of size or level of digitalization. While the federal government will provide the wallet app, integrating it into administrative systems and portals is clearly the responsibility of municipal IT departments.

The Role of Existing E-Government Portals: A Foundation, but Not a Silver Bullet

Many municipalities are not starting from scratch. Today, many already use e-government portals for online administrative processes, often as part of OZG (Online Access Act) implementations. These portals are an important lever for EUDI Wallet integration, but they do not solve the problem automatically.

E-government portals are particularly helpful in three areas:

1. A Unified Access Channel for Citizens

Portals bundle online services, application processes, and identification procedures. For the EUDI Wallet, this means:

The wallet can be integrated centrally within the portal, instead of connecting it individually to each specialist system.
Municipalities can create a consistent entry point for wallet-based identification and attribute verification.
Existing user journeys, accessibility features, and multilingual support can continue to be used.

2. Existing Identity and Authentication Logic

Many portals already work with BundID, state identity systems, and eID integrations (such as the online ID function).

These structures are beneficial because they already treat identity as a separate layer. For the EUDI Wallet, this means:

The wallet can replace or complement existing identity providers.
Portals can act as an identity broker between the wallet and administrative systems.

However, the EUDI Wallet introduces new concepts—such as verifiable credentials and selective disclosure—that go beyond traditional login mechanisms.

3. Decoupling Frontend and Administrative Systems

A key advantage of modern portals is the separation between user interface, process orchestration, and connected administrative systems.This simplifies wallet integration because:

Administrative systems do not need to communicate directly with the wallet.
Attributes from the wallet can be preprocessed and standardised before being passed on.
Existing interfaces and integrations can continue to be used.

E-government portals therefore represent part of the solution, but they still require integration into the broader public administration IT landscape. Even where such integration already exists, adjustments will be necessary.

The Real Challenge: Technical Integration

In practice, the greatest risk lies in the technical implementation on site. Typical challenges include:

1. Heterogeneous Administrative Systems and Legacy Infrastructure

Municipal IT environments often consist of:

administrative systems that are decades old,
custom adaptations for each municipality,
missing or non-standardised APIs.

However, the EUDI Wallet relies on standardised protocols and data models. These worlds must be connected—without disrupting ongoing operations.

2. Lack of Separation Between Identity and Business Logic

In many existing systems, identity verification, authorisation logic, and business processes are tightly intertwined. The wallet, however, requires a clear separation:

Identity and attributes come from the wallet.
Administrative systems consume these attributes.
Decisions are logged in a transparent and traceable way.

While this architectural change is conceptually simple, it is technically demanding—especially in legacy environments.

3. The Issuer Function Is Much More Than “Digitising a PDF”

Certificates for the wallet are not simple documents, but cryptographically signed credentials with defined life cycles:

Issuance
Update or revocation
Verification of validity by third parties

If central services are not (or cannot be) used, municipalities will need:

secure key management,
integration with registers and administrative systems,
audit-proof processes.

Without appropriate platform components, this can quickly lead to isolated solutions or security risks.

4. Security, Data Protection, and Operations

Wallet integration involves highly sensitive data, which results in strict requirements for:

IT security (BSI standards, eIDAS, Zero Trust),
data protection (data minimisation, purpose limitation),
availability and scalability.

To manage the complexity of direct wallet communication, eIDAS 2.0 introduces the role of the intermediary. This intermediary acts as a “trust bridge”, reducing technical complexity while ensuring the highest data protection standards through stateless data processing.

What Helps Now: Standardisation with Room for Individual Needs

The good news is that municipalities do not have to solve this challenge alone. The key is an approach that consistently uses standards while still reflecting the realities of municipal IT environments.

The following principles have proven effective:

Middleware instead of modifying administrative systems: An intermediate identity and credential layer decouples the wallet from backend systems.
Open standards: Avoiding proprietary dependencies while ensuring compatibility with state and federal infrastructures.
Modularity: Municipalities can start with wallet acceptance and later expand to issuer functions.
Flexible operating models: Trusted intermediaries and architecture components can be deployed on-premises, in the cloud, or in hybrid environments.

adorsys supports exactly this approach—with carefully selected EUDI components that integrate into existing public administration IT systems. This ranges from wallet acceptance and issuer components to secure key and certificate management.

Architecture Overview: How the EUDI Wallet Integrates into Government IT

To integrate the EUDI Wallet efficiently and at scale, a multi-layer architecture has proven effective. It works both online via government portals and on-site at service counters, without requiring administrative systems to communicate directly with the wallet.

Common Architecture Principles

One wallet integration, many administrative systems
Centralised security and trust logic
Separation of identity, process orchestration, and business logic
Preparation for issuer capabilities

This architecture allows the EUDI Wallet to be integrated into production within a few months and then expanded step by step. The technical integration is not a standard off-the-shelf product but requires a tailored architecture and the right choice of partners.

What Does a Typical Implementation Project in a Municipal Administration Look Like?

In practice, the following compact approach has proven effective while taking existing government IT systems and service providers into account:

Orientation & Target Architecture (1–1.5 months)

Identify and prioritise the affected administrative systems
Analyse existing portals, identity solutions, and infrastructure
Define a viable target architecture based on standardised components

Implement Wallet Acceptance (2–3 months)

Integrate the EUDI Wallet with the e-government portal or via standardised middleware
Integrate it into selected, frequently used online services
Provide data endpoints for local systems and service desk workstations

Optional Issuer Functions (2–4 months, focused)

Start with a few clearly defined credentials (e.g., registration certificates)
Use prebuilt issuer, key, and certificate management components
Establish a reusable foundation for additional credentials

What matters most is not speed, but a clean architecture that allows future extensions without launching entirely new projects. adorsys supports this process early on—for example through an architecture review, assessing existing portals and interfaces for EUDI readiness.

IT Coordinators Need to Act Now

The obligation to accept the EUDI Wallet will come into force this year and will significantly impact the IT architecture of public authorities and municipalities. Organisations should act now to avoid rushed individual projects and costly retrofits later.

adorsys is your competent and reliable partner for consulting, technical implementation, and support. Together, we will find the solution that best combines regulatory compliance, technical integration, and economic efficiency.

Feel free to contact us for an initial consultation or workshop.