1.INTRODUCTION The Single Market is one of the EU’s greatest accomplishments, promoting growth and improving the daily lives of businesses and citizens alike through its guarantee of the free movement of goods and services. However, barriers to cross-border activity still persist, with administrative burdens placed on both organisations and individuals as they interact with public administrations in other EU Member States. Regulation (EU) 2018/1724 establishing a single digital gateway (Single digital gateway Regulation, or SDGR) aims at facilitating online access to information, administrative procedures and assistance services that citizens and businesses need to get active in another Member State. It sets out an obligation on the Commission to establish, in cooperation with Member States, a technical system allowing a cross-border automated exchange of evidence and application of the ‘once-only’ principle (the once-only technical system or OOTS). This system will substantially facilitate the use of online procedures as the citizens and businesses will not have to supply cross-border evidence which is already kept by the relevant competent authorities of any Member State. Article 14(9) of the SDGR contains an empowerment for the Commission to lay down technical and operational specifications of the OOTS in an implementing act. This technical system will provide considerable help for users of online procedures, falling under the scope of Article 14, by facilitating and speeding up their interactions with competent authorities. However, the system will also have a significant resource impact on the competent authorities who will need to implement it. The aim of this Staff Working Document is to provide an overview of costs of implementation of those parts of the OOTS for which Member States will be responsible. The document is based on the results of the Member States Readiness Study which thoroughly assesses the current situation in the EU Member States. The SWD presents, in its Annex, the high level roadmap describing different implementation options that Member States could choose to implement the OOTS and the costs estimation developped for each Member State, which were prepared as part of the Study. 2.The once-only technical system The architecture of the technical system is shown below (Figure 1). The left side of the scheme shows the main architectural components managed by Member State A (MS A) - the evidence requester - while the right side displays the components managed by Member State B (MS B) - the evidence provider. The EU components are shown in the centre of the figure and provide information on how and where the evidence requested by Member State A can be retrieved from Member State B. To realise the cross-border interaction that enables evidence to be exchanged over the public internet in a secure way, Member States need to develop on both sides: the requester and and provider, functional components and the related connections with the common/core services hosted and operated by the European Commission (using specific application programming interfaces- APIs). Figure 1: High-level Architecture of the OOTS To summarise, the Member States are responsible for the development or upgrade of the following components of the OOTS: 1.Online procedure portal and its back-end, including a preview area; 2.Cross-border evidence exchange infrastructure (eDelivery Access Points); 3.Data services and 4.Data sources. Additionally: ·The eIDAS node should be used as the cross-border authentication system, implemented under the eIDAS Regulation; ·New or existing data exchange infrastructures (also known as intermediary services) can be used to retrieve the evidences from the respective data sources within a country’s borders (accessing national base registries or local databases).

The EC common components are the following (represented in blue in the figure): 1.Evidence Broker; 2.Data Service Directory; 3.eDelivery Common Services and 4.Semantic repository. 3.Implementation Roadmap Overall, the following general high-level implementation roadmap of the OOTS functional components is generally common to each Member State, structured in five main phases and related steps. Figure 2 presents the overall approach that Member States could adopt: Figure 2: High-level SDG roadmap for Member States 4.Implementation Options The table below summarises the main implementation options for each OOTS functional component under the responsibility of Member States. SDG Component in charge of MSs Implementation strategies – title and description Procedure Portals & backend ·Option 1 - Create or readapt a single national portal Develop or reuse one National Portal as single point of contact in which all the procedures are available. The Portal backend will be developed or readapted, according to the case, in order to provide all the functionalities required for the integration with the SDG technical system. A. ·Option 2 - Readapt existing portals - readapt frontends and develop one backend Reuse multiple existing portals at different government levels (regional, universities, national, etc.). Readapting the individual portals could require a high cost, which may be reduced using different strategies. For instance, by publishing the technical specification and the main source code for one general eGov portal to be then readapted at all level or MSs may use a Service Oriented Approach (SOA) approach developing the main functionalities as reusable services for all the portals. Two possibilities are available: ·Option 2: develop from scratch a single backend and readapt each frontend of the existing portals; ·Option 3: readapt frontend and backend of all the existing Portals. B. ·Option 3 - Readapt existing portals - readapt frontends and backends Cross-border data exchange infrastructure (eDelivery) ·Option 1 - Develop a specific eDelivery AP(s) for cross border interaction Develop one eDelivery Access Point dedicated to the exchange of evidence through the OOTS. The Access Point will allow the cross-border exchange of evidence both in the evidence requester side (forwarding the request of evidence to the eDelivery AP of another MS and receiving the evidence) and evidence provider side (receiving the request and then forwarding the evidence to the eDelivery AP of the requesting side ). C. ·Option 2 - Reuse existing eDelivery AP(s) for cross border interaction Readapt one or more existing eDelivery Access Points to allow the cross-border interaction of evidence. D. ·Option 3 - Develop new and reuse existing eDelivery AP(s) for cross border interactions Develop and readapt different eDelivery Access Point (s) dedicated to the exchange of evidence through the OOTS Data service ·Option 1 - Develop one Data service connected to a data exchange infrastructure Develop one central Data Service managing all the SDGR requests of evidence and connect the data service to a national data exchange infrastructure. The data exchange infrastructure will retrieve the requested evidence from the specific data source / base registry of the country. E. ·Option 2 - Develop one Data service directly connected to evidence providers Develop one central Data Service managing all the requests forevidence that is directly connected to the evidence providers’ base registries and data sources in which the evidence is stored. This solution does not make use of any national data exchange infrastructure. National data exchange infrastructure ·Option 1 - Develop a new national data exchange infrastructure Develop from scratch a national data exchange infrastructure that can simplify the retrieval of evidence within the country borders (located in the country base registries or local data sources). F. ·Option 2 - Reuse an existing national data exchange infrastructure Reuse an existing national data exchange infrastructure to retrieve the evidences within the country borders (located in the country base registries or local data sources). ·Option 3 - do not use a national data exchange infrastructure This option foresees not to use a data exchange infrastructure to retrieve the evidences within the country borders. The data service will be connected directly to base registries and data sources. Table 1: Implementation options for each OOTS national component 5.Key Determinants for the Cost Calculation A key factor affecting the scale of the challenge that Member States face is the number of endpoints (e.g. individual organizations’ data sources, national base registries, national web portals etc.) that must be connected to this new infrastructure. As detailed information on this number of endpoints is not available, the number of organisations that it is estimated should connect to the OOTS is used as a proxy for the number of endpoints. These organisations may connect as either “evidence requesters” (data consumers; organisations that request and receive evidence from other public organisations) or “evidence providers” (data providers; organisations that share evidence and data with other public organisations). According to estimates, there are 14570 evidence requesters and 23120 evidence providers that must connect to the OOTS across the EU27 . However, there are considerable uncertainties (see Figure 3) around these estimates due to continued lack of clarity about the organisations responsible for procedures under the scope of Article 14 SDGR and evidences in some Member States.

Figure 3: Total estimated number of data consumers and providers across the EU-27 The large estimates of the number of evidence requesters and evidence providers are driven by just a few Member States (e.g. Italy, Germany, Spain) for which some of the procedures and evidences are handled at a local level involving hundreds or thousands of organisations. They are also driven by a few procedures (e.g. notification of business activity) and evidences (e.g. birth/marriage certificates or university diplomas) which are most likely to be managed at a local level across a number of Member States. On the other hand, key infrastructures exist in Member States which can facilitate their efforts to connect their data providers to the OOTS. In 20 Member States, national data exchange infrastructures have been identified which are used within the Member State to share data between public administrations. These infrastructures can potentially be used as a central hub for data exchange between public authorities within a Member State and the OOTS. 6.implementation Assumptions for the cost assessment Certain assumptions about the choices that Member States will make in relation to the key components of this architecture are built into the costs. These components are the procedure portal and back-end, data service and national data infrastructure, and eDelivery access point. Where possible, these assumptions are based on stated Member State preferences. However, when these preferences are not known, options were selected based on the below recommendations: ·Procedure Portal & Backend: The least costly option is to use a single national portal for all procedures. This option may not be feasible for all Member States due to organisational or legal barriers. However, if there are a large number of evidence requesters, the rationale to pursue this approach is very strong. Table 2 shows how the one-off costs associated with this component are expected to increase for an “average” EU Member State as the number of portals to adapt increases. For all Member States with a large number of evidence requesters (above 250), it has been assumed the single national portal strategy. If a Member State cannot use a single national government portal and must readapt numerous existing portals, the re-engineering will lead to high investment costs and complexity. The recommendation, if following this strategy, is therefore to coordinate the work of the local public administrations, providing them with guidelines, technical specifications, and reference software so that they can develop one single back-end and integrate it with the existing front-end portals. The rationale for this approach also becomes stronger (compared to a multiple back-end approach) if the Member State has a high number of evidence requesters that must connect to the OOTS. Table 2: Procedure Portal costs across different implementation options ·National data exchange infrastructure and data service: Costs are reduced if a national data exchange infrastructures as a single hub between the data service component and the data sources is used to connect to the OOTS. If a Member State does not have an existing data exchange infrastructure at national level, designing and implementing one should be considered, as such an infrastructure is one of the most important enablers to retrieve evidence within Member State borders. Member States will benefit from this implementation (no matter the number of data sources to be integrated) since the experience from several Member States suggests that a national data exchange infrastructure provides a more uniform way to manage the exchange of data in a Member State. ·Table 3 shows the costs for an “average” EU Member State with different numbers of data sources of using a data exchange infrastructure (whether a new one or an existing one) compared to directly connecting the data sources to the data service component. The data service and/or data exchange infrastructure must be integrated with the individual evidence providers. To reduce integration and maintenance costs, Member States should consider, when possible, to centralise evidence in national (or sectorial / regional) base registries. Table 3: Data exchange infrastructure and data service costs across different implementation options ·eDelivery Access Point: The costs of deploying and maintaining this component are relatively marginal compared to the costs related to the other components. However, the eDelivery Access Point is a crucial enabler for the cross-border interaction among Member States. A centralised approach, using a single access point, could be the best option to reduce system complexity and the overall costs of maintaining and operating the access point.





7.Total estimated cost for Member States Based on these factors and the identified implementation options, the total cost for Member States to connect to the OOTS has been estimated. The cost estimations provide a preliminary understanding of the rough budget needed for the implementation of the OOTS components for which Member States are responsible. For all cost estimates provided, there is a range (from half the estimated cost to double the estimated cost) within which the true cost is expected to fall. To have an accurate and detailed cost estimation, each Member State would need to proceed with a thorough feasibility study in order to consider the options and specificities at national/regional/local level. The cost estimates can be broken down into one-off costs and yearly running costs. The high-level cost estimates differ considerably across Member States. The estimated one-off costs for Member States range from a low of €2,9 million for Greece (with a yearly running cost of 0,9 million), to a high of €92 million for Germany (with a yearly running cost of €24,3 million). The mean one-off cost for a Member State is €14,6 million, with a mean yearly running cost of €4,2 million. However, as can be seen in the graph below, most of the cost across the EU is attributable to just a few Member States, in particular Germany, Italy, and Sweden. For all of these cases, this is caused by the relatively high number of evidence requestersand evidence providers that, according to the evidence collected, will need to connect in these Member States . These Member States manage at least some of the procedures or evidences in the scope of Article 14 SDGR, at a local or decentralised level, meaning that a high number of organisations would need to connect to the SDG OOP technical system.



Figure 4: Implementation of the OOTS - total cost estimate Table 4 illustrates both the estimated cost and cost range per Member State. The cost estimates are based on point estimates and assumptions about the number of evidence requesters and evidence providers in each Member State, where the full information on these numbers is not available. In the table below, the overall investment for each of the EU27 Member States is presented, also referring to their specific national ICT spending and highlighting cost ranges: Table 4: SDG OOP total cost per Member State 8.Conclusion According to the Study, the total one-off cost for the EU27 Member States to connect to the once- only technical system in line with the requirements set out in the Commission Implementing Regulation [COM/2021/xxxx] are in the order of magnitude of EUR 400 million. Yearly maintenance will amount to a total of around 112 million.