MaKo – How the Players in the Unbundled German Energy Market Communicate

The digitalization of the German energy industry encompasses a wide range of business and practical areas. One key initiative is to ensure that data can flow smoothly and securely between all parties in the electricity and gas sectors. This involves standardised processes to make sure that business transactions are time and cost efficient. A significant part of the various standardisation initiatives involves defining and regulating how information is electronically sent and received between the many players in the power industry; known as market communication (MaKo, from the German Marktkommunikation). This encompasses a long list of processes, is complex to put into practice and involves myriad players. At the same time, we also need to clearly identify and define market roles and market players to enable them to communicate with each other.

This guide aims to demystify this complex world for you. Read on for a clear overview of the who, how and why of market communication in the German energy industry.

1. What is market communication and why do we need it?

Market communication comes from the German Marktkommunikation, and is generally shortened to MaKo. It refers to the electronic interchange of files between players in the German energy market.

The processes that require this sharing of information have their roots in the liberalisation of the German energy market.

Over time, market players have adopted common processes, formats and transmission rules to enable automated, efficient communication with their counterparts.

The journey started in 2006, with the introduction of business processes to supply customers with electricity. These are known in German as GPKE. They were followed by similar processes for the gas market (shortened in German to GeLi), rules to balance gas and electricity supply (shortened in German to GABi Gas and MaBiS respectively) processes for measuring consumption (WiM) and Redispatch, which covers balancing mechanisms to ensure grid stability.

There are regular amendments to these processes, formats and transmission rules to meet the developing needs of the energy market.

Market communication is critical to running a functioning, open energy market and securing power supply. We have since celebrated over 15 years of market communication, all supported by the cross-association working group edi@energy.

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2. The history behind MaKo

In 1998, EU Directive 96/92/EC was written into national law. This set the stage for deregulating the German electricity market and was the beginning of market communication between the German energy providers. Just five years later, in 2003, the gas market was liberalised when EU directive 98/30/EG came into effect. This broke up the monopoly previously held by the local public utilities, and German households could finally choose their energy provider.  Since then, the market has been subject to competition law. In 2005, energy providers with more than 100,000 consumers were unbundled – economically separated – from the grid. This step was written into law by another amendment to the Energy Industry Act (EnWG), namely directives 2003/54/EC and 2003/55/EC.

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3. Regulation

In the energy industry, electricity and gas networks are natural monopolies. Just like telecommunications a few years earlier, liberalising the energy markets in 1998 required supervision and regulation to ensure non-discriminatory access to the networks, both local and nationwide.

Regulatory scope

Regulatory scope

The liberalised energy market is governed by the Energy Industry Act (EnWG) Part 3, “Regulation of Network Operation”. Section 4 specifies the powers accorded to the regulatory authority and the sanctions it may apply. Further details on the regulators' powers can be found in its various directives and ordinances.

The regulators

The regulators

On the 13th July 2005, the Federal Network Agency (BNetzA) was appointed the regulatory body for the newly liberalised energy industry. As the BNetzA had already been serving as regulators for the telecommunications industry, they had already gained the experience and expertiseto make them suitable to also regulate the German energy market. BNetzA defines the conditions under which electricity and gas suppliers can use the networks to supply their customers, and regulates what the suppliers charge for this. To this end, they are careful to ensure that the grid operators are able to fulfil the requirements of Germany's liberalised, greener energy industry without placing an excessive financial burden on their consumers.

How is the market regulated?

How is the market regulated?

BNetzA regulates by defining the terms and conditions under which electricity and gas suppliers can use the grids to supply customers. This includes:

  • Approving network charges
  • Stipulating and conditions and approving methods, e.g. for business processes or data exchange formats
  • Initiating proceedings if a breach is suspected or known
  • Monitoring BNetzA is actively supported in defining business processes and data exchange formats by associations including

BDEW (German Association of Energy and Water Industries) DVGW (German Technical and Scientific Association for Gas and Water), and the specialist cross-association group edi@energy under the umbrella of BDEW.

When did the rules come into effect??

When did the rules come into effect?

The liberalisation of the German energy market was a multi-step undertaking in which processes were published as they were defined. The BNetzA site goes into more detail on what happened when.


Some important milestones:

The liberalised energy market is continuing to develop as legislation changes, the regulatory framework grows in scope and there are new procedures for defining rules and processes.

Setting policy and consultation periods

Two of the most important instruments for the BNetzA are formal procedures to set and consult on policy. These formal procedures allow them to define and implement the terms under which players may access the market. The Federal Network Agency (BNetzA) drafts the policies in consultation with representatives for the various market players. These are published during a fixed-length public consultation period, during which anyone can comment on them. BNetzA then evaluates this input and may amend policies as a result. This ensures that the market players are still being heard in the very necessary work of regulating the market and creating effective processes.

A who’s who of regulators and their specific roles (What is BMWK/ BNetzA/ BDEW/ DVGW/ edi@energy?)

The following are key players in defining the processes in the German liberalised energy market and the corresponding market communication.

Bundesministerium für Wirtschaft(Federal Ministry for Economic Affairs)BMWKLegislatorMinistry in charge, key legislative player.
Bundesnetzagentur(Federal Network Agency)BNetzAFederal bodydefines the terms for electricity and gas companies to supply their customers from the grids and sets the charges in ruling chamber 6 (electricity) and 7 (gas)
Bundesverband der Energie- und Wasserwirtschaft(Federal Association of the Energy and Water Industries)BDEWAdvocacy group for the German electricity and energy industryBDEW contributes to legislative processes in the energy industry and is an active partner in shaping the BNetzA terms for grid access.
Deutscher Verein des Gas- und Wasserfaches e.V.(German Technical and Scientific Association for Gas and Water)DVGWIndustry association for the German gas and water sectorsThe DVGW's main task is to draft the technical regulations to ensure that Germany's gas and water supply is secure and reliable. In addition, the DVGW also helps shape the conditions and methods for gas grid access defined by the BNetzA.
BDEW Forum Datenformate(BDEW Forum on Data Formats)edi@energyedi@energy is a cross-association expert group under the umbrella of BDEW. It develops the data formats used in the market processes.

4. Market roles and players

BDEW has modelled specific roles to ensure that market communication in the German energy market meets all relevant legal, regulatory and technical specifications. These roles include definitions for areas and objects and makes it easier to assign responsibility and know which process to follow.

The following sections look at the most important roles, regions and objects. Take a look at the BDEW1 user guide for more in-depth information (German language only).

1 Source: Anwendungshilfe „Rollenmodell für die Marktkommunikation im deutschen Energiemarkt“[User guide: Role model for market communication in the German energy market ] Arbeitsgrundlagen Marktkommunikation Version 2.0 from 25th March 2021, BDEW e. V., P10

Market Roles

Here are the most important roles:

Balancing Group Coordinator (in German Bilanzkreiskoordinator, shortened to BIKO)

  • is responsible for balancing group accounting in the electricity sector
  • ensures the balancing group managers pay and receive the correct balancing charges.

Balancing Group Manager (in German Bilanzkreisverantwortlichen, shortened to BKV)

  • is responsible for balancing the energy and finances for the balancing groups in the electricity and gas sectors

Operations Officer (in German Einsatzverantwortlichen, shortened to EIV)

  • is responsible for deploying resources

Supplier (in German Lieferant, shortened to LF)

  • is responsible for the supply and consumption of energy from market locations (cf. objects)

Market Zone Manager (in German Marktgebietsverantwortlichen, shortened to MGV)

  • is responsible for balancing group accounting in the gas sector
  • operates virtual trading points
  • procures and controls energy reserves

Meter Operator (in German Messstellenbetreiber, shortened to MSB)

  • is responsible for installing and operating metering devices
  • is responsible for measuring consumption (including any necessary calculations) and sharing these values with market partners.

Grid Operator (in German Netzbetreiber, shortened to NB)

  • is responsible for distributing power, whether electricity or gas
  • is responsible for grid security and stability (including any necessary construction and maintenance)
  • equates to the distribution network operator (DSO) in regional transmission and distribution

Transmission system operator (in German Übertragungsnetzbetreiber, shortened to ÜNB)

  • operates the transmission system – connects power reserves (cf. zones)
  • is responsible for system security
  • is responsible for developing and operating interregional transmission systems.


The following lists the most important zones that fall under the jurisdiction of the roles described above.

Balancing zone (in German Bilanzierungsgebiet, shortened to BG)

  • is a term specific to the electricity sector
  • consists of any number of grid zones
  • is in a regulation zone

Market zone (in German Marktgebiet, shortened to MG)

  • is a term specific to the gas sector
  • combines midstream and downstream grids

Grid zone (in German Netzgebiet, shortened to NG)

  • is a defined area within a balancing or market zone

Regulation zone (in German Regelzone, shortened to RZ)

  • is a term specific to the electricity sector
  • is a defined area containing 1+ grid zones
  • balances input and output within the zone
  • ensures grid stability (load and frequency)


The following list the most important objects that fall under the jurisdiction of the roles described above.

Balancing group (in German Bilanzkreis, shorted BK)

  • balances the energy (electricity or gas) fed into and taken from the grid.


  • also known as a smart meter gateway
  • communication system which, combined with several measuring devices, creates an intelligent system, which transmits encrypted meter readings and received and forwards information.

Market location (in German Marktlokation, shortened to MaLo)

  • the place where energy (electricity or gas) is generated or consumed
  • is connected to the grid
  • can have any number of measuring stations

Measuring station (in German Messlokation, shortened to MeLo)

  • place where energy is measured (electricity or gas)
  • has all the measuring equipment needed to determine and, if necessary, submit measurements (cf. gateway)
  • can be attributed to any number of market locations

Meter/measuring device

  • Part of a measuring station for determining power consumption
  • We differentiate between:
    • conventional meters, such as the Ferraris counter, an induction meter which has been used in Germany for decades. Sometimes a conventional meter is connected to the communication network, e.g. for direct metering.
    • modern meters. These are digital electricity meters. As well as measuring consumption, they also show information like usage per day, week, month and year. This lets the consumer keep close tabs on his power consumption. If used with a smart meter gateway, we refer to that setup as an intelligent measuring system.

How are market players identified?

The roles above receive distinct identifiers. The BDEW subsidiary Energie Codes und Services GmbH is responsible for allocating identifiers for the electricity industry. You can contact them through the website

DVGW Services und Consult GmbH is responsible for the gas market. You can contact them through the website DVGW Codevergabeportal: Startseite (

The two companies above also allocate identifiers for market locations, regardless of the actual sector.

5. Processes in market communication

A liberalised energy market requires coordinated, functioning processes for all parties to function properly. BNetzA, working closely with such groups as BDEW, DVGW, and the cross-association working group edi@energy, have defined the processes below. These groups continually amend these processes to meet new requirements and insights.

The processes are categorised by task and target group. The descriptions take into account the different requirements of the electricity and gas sectors. There are currently following processes:

AbbreviationFuel sectorDescription
Business process for supplying customers with electricityGPKEElectricityProcesses allowing suppliers access to the grid and for supplying electricity to end customers.
business process for switching gas supplierGeLiGasProcesses allowing suppliers access to the grid and for supplying gas to end customers.
Changes in meteringWiMElectricity, gasProcesses relate to operating meters, including changing operator or device and collecting meter data. Some processes are described in the GPKE and referred to by WiM.
Market regulations for balancing electricity supply MaBiSElectricityProcesses related to balancing group
Balancing GasGaBi GasGasProcesses related to balancing in the gas market
Market process for electricity generator locations MPESElectricityProcesses related to assigning generators to suppliers in direct marketing
Guarantee of origin registerHKNRElectricityGrid operator communication pertaining to the guarantee of origin register held at the Federal Environment Agency.
Redispatch 2.0Redispatch 2.0ElectricityProcesses and measures for securing grid stability. These include changes to scheduled power plant use to prevent energy bottlenecks.

In the main, communication is in an EDIFACT  format. Some Redispatch 2.0 processes (adopted 2021) use XML. The XML structures follow ENTSO-E specifications.

edi@energy publishes the message types for the above processes, while data formats for the gas sector (GaBi Gas) are published by DVGW's wholly-owned subsidiary, DVGW Service & Consult GmbH.


GPKE stands for Geschäftsprozesse zur Kundenbelieferung mit Elektrizität (business processes for supplying electricity to customers) while GeLi Gas stands for Geschäftsprozesse Lieferantenwechsel Gas (business processes for switching gas supplier). Both describe the main processes and corresponding electronic data interchange for switching supplier.

The business processes for both the above involve:

  • Balancing Group Manager (BKV)
  • Supplier (LF)
  • Grid operator (NB)
  • Meter operator (MSB)
  • Transmission system operator (ÜNB)

They encompass the following tasks:

  • Terminating old contract (done by the new supplier on behalf of the customer)
  • Supply end date (either due to switching supplier or another reason for cutting supply)
  • Supply start date (either due to switching supplier or another reason for beginning supply, e.g. a new-build)
  • Substitute supply (so consumer still has an energy supply if new supplier is not known– as regulated by safety-net and substitute supply clause §38 of EnWG)
  • Reading meter and passing on consumption level
  • Grid usage billing (billing of grid usage fees to grid user)
  • Updating and sharing master data
  • Business data request (request for master data or readings from market or measuring stations)

MaBiS / GaBi

MaBiS is a set of regulations for managing the balancing group, balancing rules and balancing group settlement for the electricity sector. GaBi Gas is the equivalent for the gas sector.

These involve the following players:

  • Balancing Group Coordinator (BIKO) / Market Zone Manager (MGV)
  • Balancing Group Manager (BKV)
  • Supplier (LF)
  • Grid Operator (NB)
  • Transmission system operator (ÜNB) /(FNB)

MaBiS encompasses the following processes:

  • Data exchange processes for balancing zones(registration/deregistration of balancing zones, balancing group allocation)
  • Data exchange processes for time series (activating/deactivating MaBiS metering points, reconciling and submitting network time series)
  • Data exchange processes between grid operator and supplier (or transmission system operator) (exchanging/transmitting standardised profiles, bands and profile definitions)
  • Data exchange processes between transmission system operator and supplier for supplier time series and clearing list
  • Data exchange processes for balancing totals time series
  • Data exchange processes for delta time series transfer
  • Data exchange processes for settlement totals time series
  • Exchange balancing energy prices
  • Data exchange processes for daily balancing zone totals time series
  • Data exchange processes for daily balancing group totals time series
  • Data exchange processes for REDISPATCH balancing

GaBi Gas involves the following processes:

  • Declaring quantity
  • Standardisation
  • Changing capacity
  • Declaration lists
  • Declaring surplus/ shortfall


WiM stands for Wechselprozesse im Messwesen and describes the central processes and associated electronic data interchange involved in metering, if these are not otherwise defined in GPKE. These essentially involve switching the metering point operator and changing metering equipment. The processes are slightly different for electricity and gas.

WiM involves the following players:

  • Meter Operator (MSB), Default Meter Operator (gMSB)
  • Grid Operator (NB)
  • Supplier (LF)
  • Transmission system operator (ÜNB)
  • Energy service provider to consumer (ESA)

WiM encompasses the following processes:

  • Terminating a metering point
  • Start metering point operation
  • End metering point operation
  • Obligations as default meter operator
  • Supplementary processes for metering point switchover:
    • Change device and
    • Transfer device
  • Changes to measuring stations, whether conventional measuring devices (kME), modern measuring devices (mME) or intelligent measuring systems (iMS), encompassing installation, upgrade and calibration
  • Installing a modern measuring device into an existing measuring station
  • Installing an intelligent measuring device into an existing measuring station
  • Billing for metering point
    • Sending price list data for an intelligent or modern measuring device
  • Billing for an intelligent or modern measuring device
  • Overarching processes
    • Troubleshooting and error resolution for a measuring station


MPES stands for Marktprozesse für erzeugende Marktlokationen Strom (processes for generating market locations, electricity) and define the processes relevant to direct marketing. The processes apply to any electricity generator, whether CHP or renewable energy, from which the power can be marketed in full or part straight to the consumer, i.e. the consumer can change suppliers. We differentiate between plants who must sell their power through direct marketing, and those who may.

If a situation arises for which there is no provision in MPES, the rules in GPKE and WiM apply. In this case, substitute:

  • generation for supply
  • generate power for consume power
  • generator for end user


  • Balancing Group Manager (BKV)
  • Supplier (LF)
  • Network Operator (NB)
  • Meter Operator (MSB)
  • Transmission system operator (ÜNB)
  • Generator (EZ)


  • Registration for direct marketing
  • Cancellation
  • Begin supply
  • End supply
  • Auditing an EEG market location with an obligation to full direct marketing which only has one supplier


Processes pertaining to the guarantee of origin register involve EDIFACT communication with the Federal Environment Agency.


  • Grid Operator
  • German Environment Agency (Umweltbundesamt, shortened to UBA)


  • Requests from German Environment Agency for master data or meter readings
  • Grid operators sharing master data with German Environment Agency
  • Sending meter readings to power generators
  • Cancelling subscription-based transfers of records or readings

Redispatch 2.0


  • Operations Officer (EIV)
  • Data Provider (DP)
  • Power Generator Operator (ANB)
  • Grid Operator (NB)
  • Supplier (LF)
  • Balancing Group Manager (BKV)
  • Technical resource operator (BTR)
  • Transmission system operator (ÜNB)
  • Balancing Group Coordinator (BIKO)

Significant processes

  • Exchanging master data records, planning records and non-usage (EIV-NB)
  • Transmitting and forwarding meteorological data
  • Determining and reconciling downtime relevant for accounting
  • Changing balancing or accounting model
  • Redispatch balancing processes

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6. Data formats

With the exception of the Redispatch 2.0 processes introduced in 2021, EDIFACT is the syntax used in market communication. Specifications are defined and published by edi@energy and include the following EDIFACT formats:

  • UTILMD (utilities master data message) – exchanging data on customers, contracts and meters
  • UTILTS (utilities time series message) – Transmitting formula for calculation
  • MSCONS (metered services consumption report message) – meter readings, energy quantities
  • ORDERS (purchase order message) – orders
  • ORDRSP (purchase order response message) - purchase order response
  • QUOTES – quotations
  • REQOTE (request for quote) – request quotation
  • INVOIC (invoice message) – invoices for grid and energy services
  • REMADV (remittance advice) – remittance advice
  • COMDIS (commercial dispute message) – helps clarify why an invoice has been rejected
  • PRICAT (price catalogue message) – price lists for balancing and metering services
  • IFTSTA (status of transport) – message tracking
  • INSRPT (inspection report) –used to communicate technical faults in a measuring station or known by an operator
  • APERAK (application error and acknowledgement message)
  • CONTRL – confirms syntax and successful sending

The gas sector uses further formats, as defined by DVGW Service & Consult GmbH. These include:

  • ALOCAT (based on ORDRSP) – Information on quantity taken
  • IMBNOT (based on ORDRSP) – Balance/imbalance message to balancing group coordinator or grid operator.
  • SLPASP (based on ORDCHG) – supplies parameters to calculate allocation
  • SSQNOT (based on ORDRSP) – Reporting excess/shortfall quantities
  • TSIMSG (based on UTILMD) – Declaration list for balancing group management in the gas sector

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7. Communication

The technical side of how the market communicates is set out in Regelungen zum Übertragungsweg (communication method/protocol regulations) and Allgemeine Festlegungen (general provisions), both on the documents page of the edi@energy website. The document specifies the security and protection mechanisms required for electronic data exchange in regulated processes between market partners in the German energy industry.

Communication methods and/or protocols include AS2, e-mail via SMTP, SFTP and REST. AS2 and e-mail over SMTP are used in a number of energy market processes, whereas SFTP and REST are only permitted in Redispatch processes. Communication should always be encrypted and signed.

An important aspect of communication in the German power industry is having a single point of contact. This means that there is only one set of contact details per member ID. A grid operator in the electricity sector, for example, is only able to specify one e-mail address.

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8. Format changes

The processes, formats and transmission protocols are not static. They are constantly being updated to reflect changing regulations and requirements. These changes and extensions come into effect at scheduled points throughout the year.

Changes apply equally to all market participants. To ensure that everyone has the same understanding of current regulations, processes and formats and that there are not several different versions in circulation, changes come into effect on fixed dates.

Unless otherwise specified, changes to format, processes or regulations only come into effect on either the 1st April or 1st October of a given year. All market participants must have switched to the new formats, processes etc. by the set deadline as the older versions immediately become invalid and may no longer be used.

The amendments are published by the BNetzA, or edi@energy, on behalf of BNetzA. There is always a consultation phase beforehand which lets participants have their say.

9. What is the difference between technical and content-based MaKo?

We differentiate between technical and content-based market communication

Content-based MaKo

Content-based MaKo refers to business processes as defined in e.g. the GPKE. These are processes that take place in various departments and are – generally – set out in an ERP system. These processes generate data that is passed on in an agreed format. You can find documents on cross-sector processes and the processes used in the electricity sector here, and for the gas sector here.

Technical MaKo

Technical MaKo refers to transmission protocols and converting data into the relevant formats (EDIFACT, XML). Rules governing technical MaKo can be found on the edi@energy website. Technical MaKo also includes compliance tests. These include the CONTRL syntax and service report. There are also checks to ensure parties are adhering to the rules in the user handbooks. The user handbooks contain regulations on the expected content and qualifiers for specific processes.

10. FAQ MaKo AS4


1. 1. Which changes apply with MaKo 2023?

  • AS4 communication replaces AS2 and email communication in the electricity sector.
  • All market participants need to set up a new connection to each of their communication partners.
  • AS4 communication to be encrypted with ECC Brainpool (elliptic curve cryptography).
  • Certificates are used within the smart meter public key infrastructure (PKI).
  • Participants will need to obtain new certificates.
  • MaKo to become part of the smart meter public key infrastructure (SM-PKI).
  • Private keys must be secured in the hardware security module (HSM).
  • Take a look at this SEEBURGER AS4 blog article to discover more.



2. Is the October 2023 deadline likely to be postponed again?

  • So far, there has been no talk of further delaying MaKo 2023.


3. Will the migration period be extended to April 1, 2024?

  • The AS4 migration period will not be extended.


4. The technical implementation process is due to run from October 1, 2023 to March 31, 2024. Can I start using the new communication format before October 2023?

  • You may enter mutual agreements with partners to use the new transmission path before October 1, 2023. However, you may not discriminate in any way against partners who do not introduce the format ahead of schedule.


5. What happens if I’m not able to communicate via AS4 as of October 1, 2023? Can I refer to the "transition period" until March 31, 2024?

  • There is no “transition period.” There is a migration period from October 1, 2023 to March 31, 2024. All market participants are required to be able to communicate via AS4 starting October 1, 2023. SEEBURGER does not know how the BNetzA will deal with market participants who do not meet the deadline.


AS4 profile

6. What do I need to switch to AS4?

  • You need an AS4 adapter that supports ECC Brainpool. The SEEBURGER adapter already supports this type of encryption.
  • You need a hardware security module (HSM) to generate and store private keys.
  • You need new certificates from the Federal Office for Information Security’s smart meter public key infrastructure.


7. Where can I find details of the AS4 profile? Is this available to view anywhere?

  • You can find information on the AS4 profile for MaKo on the edi@energy page.


8. Does AS4 use the push or pull method?

  • MaKo only uses the push method.


9. Is the URL in the certificate the AS4 address or web address where I can get the AS4 parameters?

  • The URL is the same as the AS4 address used for communication.


10. When can I consider a file „delivered“ through AS4? Is there a time stamp I can refer to?

  • Your file has been successfully transferred via AS4 if you receive a synchronous, non-repudiation receipt (NRR).


11. As with smart meters, do I have to provide a separate host name for each connection?

  • Each endpoint, i.e. each individual partner ID, requires a hostname.



12. What is HSM?

  • HSM is an acronym for Hardware Security Module. This is used to generate and store private keys.


13. Can my company only use one HSM?

  • A company can use multiple HSMs. There are no restrictions to the number you can use.


14. Can I use the same HSM for smart meter communication and MaKo?


15. What HSMs can I use?

  • From what we know so far, you can use any HSMs that have already been approved for SM-GW communication by the BSI.


16. Can I implement and use one HSM for multiple organizations and customers or are there scenarios that require two or more HSMs?

  • You can use one HSM for several organizations and customers.


17. From now on, will every MaKo process via AS4 access my HSM in order to retrieve the certificate information?

  • All cryptographic operations that need a private key take place within the HSM.


18. The CP was published by the BSI in March 2023. It describes that no HSM and no process can be streamlined for "smaller scenarios." How exactly is that to be interpreted, since some passages of the CP also contradict each other?

  • Contradictory passages from the CP related to storing the keys for communication with the sub CA, and not for market communication, will be corrected.


19. Why did SEEBURGER opt for an HSM instead of an alternative cryptographic module (smart card or server)? According to the definition, passive external market participants (EMT) do not fall under security level 2 but only under security level 1, which means that using a certified HSM is not mandatory?

  • For the MaKo AS4 service, SEEBURGER opted for an HSM certified for the smart meter PKI because we want to provide our customers with proof of compliance with the requirements for the cryptography module at any time. An HSM certified according to the PKI specifications fulfills the requirements and can be proven by the certification and the manufacturer's declaration.



20. Which sub CAs can I use for MaKo and from when?

  • Find more information on all sub CAs in this list from the Federal Office for Information Security (BSI): Sub CA list.


21. Is there a specification or a process on how to apply for the certificates?


22. Can the TLS-SSL certificate for an incoming AS4 https endpoint come from a free CA, or does it need to come from the BSI PKI?

  • You must use a TLS certificate from the smart metering public key infrastructure (SM-PKI).


23. Do I actually need a separate AS4 certificate for each role or division? This field has always been optional for AS2?

  • The certificate policy for the smart meter PKI stipulates an individual AS4 certificate for each MP-ID – i.e. also for each division – as the MP-ID must be maintained in the certificate.


24. Will there be permanent AS4 certificates? Or will they also expire after a certain period and need to be re-obtained?

  • From what we know so far, the AS4 certificates will expire after two years.


Migration scenarios

25. What can I do if market participants are still not able to use AS4 after October 1, 2023, or if my own company has not migrated to the new messaging protocol yet?

  • There are no clearly defined rules or consequences for this scenario. However, it is obligatory to have fully migrated by March 31, 2024 at the latest.


26. How is the migration phase organized? Who reports to whom, and when?

  • The BDEW has issued recommendations for dealing with migration. However, essentially “the market has to organize itself”. You are therefore expected, to plan time for queries and delays into your project plan.


27. Where can I find the BDEW recommendations for the migration period?


28. What is the process for automated migration to AS4 after the test period, or after a request for migration has been issued?

  • The conversion service sends a conversion request to the partner. Your partner confirms the request, after which you can use AS4 to communicate in both directions.


29. Can I completely delete email communication data during the migration period?

  • Please ensure a fallback option to email in the unlikely case that an error occurs during the migration period of October 2023 to March 2024.


30. Can I still maintain email communication after migrating to AS4? If so, would you recommend doing so?

  • Incoming email communication should be kept open during the migration period. However, we recommend monitoring these emails so that market participants who have supposedly switched to AS4 do not send them to the mailbox. As of April 1, 2024, according to BNetzA specifications, you must not communicate via email anymore and hence the mailbox shall be closed down.


31. 31. What if a market participant can’t be contacted via AS4, i.e. retry continues to fail?

  • If the connection fails even after repeated attempts, the sender receives an error notification. However, if only a single transmission fails, this does not mean that the whole market communication has been disrupted!


32. When will there be a switch back to email?

  • A temporary switch back to email communication can only be done if one of the two partners has identified a disruption in the market communication and has also declared it as such. This temporary email communication will be carried out in mutual agreement and as soon as the fault has been rectified, the system will be switched back to AS4 in a likewise mutual agreement. This regulation applies to the changeover phase.



33. Have there beeninteroperability tests with other manufacturers?

  • SEEBURGER is in contact with other manufacturers and service providers as well as via various working groups, such as BDEW, EDNA. The tests are ongoing.


34. Are there exemptions for certain market participants or limitations for SMEs?

  • No, there are no exemptions.


35. Where is the data decrypted?

  • In the HSM.


36. Why are there two versions of the regulations for the transmission paths? Which one is valid?

  • Both will be valid.
  • RzÜ from version 2.x regulates the AS4 communication for MaKo in the electricity sector.
  • RzÜ from version 1.x regulates the communication for MaKo in the gas industry which has not yet changed, Redispatch 2.0.


37. What are the e rules for the gas industry?

  • RzÜ 1.x continues to apply to the gas industry.We currently have no information when they are implementing AS4.


38. 38. I found this in the latest BDEW documents: “Deadlines for the market migration: Within six weeks after the start of the migration period or parallel operation, all market partners should have migrated their communication to AS4 by migrating communication with all market partners to AS4 one after the other using the “Change of transmission path” service.” Is the migration period just six weeks long rather than half a year? Or is this statement no longer applicable?

  • The application help is to be seen as a recommendation. The migration period runs until March 31, 2024. However, you may consider migrating as many partners as soon as possible.


39. Will there be a central address service?

  • The German BNetzA is not planning to have a central address service for retrieving AS4 communication data. Therefore, you must separately store and continuously update all data per MP-ED for each of your market partners.


40. The TSOs have already announced that the exchange of schedule data must also be exchanged via AS4 as of 2024. Is this also part of the MaKo Cloud Service for AS4 delivery?

  • At the technical level of AS4 communication, the SEEBURGER AS4 Service also supports the requirements for AS4 communication in schedule management. However, since the AS4 service is designed on the basis of the specification for MaKo in the electricity sector and the requirements for schedule management were not known at this time, this use case is not yet in scope.


41. The 24-hour supplier change process is currently in consultation. What impact does this have on market communication?

  • The effects on MaKo are not yet known, as the individual process steps have not yet been defined. However, this has no effect on today's MaKo.


Connection to the SEEBURGER AS4 Cloud Service

42. How do I connect to the AS4 cloud service?

  • Connect via AS2 or a REST service.


43. Why should I connect via AS2 or REST only, excluding email and any other protocol?

  • The connection specifications are based on the specifications of the BSI CP external market participants: "With such a system structure, care MUST be taken to ensure that the data exchange between the service provider and the client has a security level comparable to the security mechanisms defined in [TR-03116-3].” TR-03116-3 refers to TR-02102, which states what is “secure” and for how long from the BSI’s viewpoint.

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