Tariff use cases: TAF 1 to 16 and version 2.0

What a tariff use case is

"Gateway with TAF 1, 2, 6, 7, 9, 10 and 14." That is roughly how manufacturers describe their devices¹, and the line says nothing about what the device measures. It doesn't need to. The numbers say it, at least to anyone who knows the guideline.

The term is older than the rollout. The first version of the guideline, dated 18 March 2013, already had the list, TAF 1 to 10 mandatory and TAF 11 to 14 optional³; the idea was one device that does it all.

On 16 January 2019 the BSI added an Annex VII. Its device profile "Basis" kept only TAF 1, 2, 6 and 7 mandatory and made everything else optional³. The mandatory rollout started on exactly this profile in 2020, and a year later the Higher Administrative Court of North Rhine-Westphalia held the very same profile to be unlawful³ (chapter 1 tells the story).

The practical consequence is awkward. A TAF is a certified software function. It reaches the field through a firmware update, the hardware alone tells you little, and what a given gateway can do today depends on the version of the guideline it was last certified against.

Every tariff use case at a glance

The table shows the catalogue the way manufacturer sources list it, and next to it what version 2.0 of 13 December 2024 has made of it⁵. Behind "mandatory from 2027" sits the level MUSS+. Gateways certified against the new version from 1 January 2027 must support the function⁶; whether it then runs in the field is another matter, and the last section deals with it.

The descriptions draw on both versions of the guideline and on manufacturer sources^5,7,1. Older overviews assign some numbers differently; in 2019 the FfE, for instance, filed TAF 9 under controllable devices⁸.

And what the guideline doesn't describe itself? Version 2.0 leaves a door open for that: a gateway may implement further tariff use cases if supplementary BSI documents describe them⁵. The note on TAF 5 and 16 is just such a document.

Billing: the workhorses and the prepaid case

Four functions carry billing, and they are the same four that became mandatory in the "Basis" profile in 2019.

TAF 1 is the leanest case. The gateway sends only single meter readings, in version 2.0 once a month plus at the start and end of the term, for electricity as well as gas, water and heat⁵; nothing more leaves it. That's how the gateway was once meant to work for households. Since the GNDEW, though, metering points with a smart metering system and up to 100,000 kWh a year are metered by a series of register readings or, where available, by quarter-hourly registering load profile metering¹⁰. In the gateway that is usually TAF 7 (chapters 6 and 7).

TAF 2 adds fixed time windows, peak rate by day and off-peak at night: basically the old two-rate meter gone digital. A dynamic electricity tariff needs more, because its price follows the exchange and the exchange doesn't care what time it is.

TAF 6 fetches readings on request, typically when a customer moves or switches supplier.

The real workhorse is TAF 7. It delivers meter readings for consumption and generation every quarter hour (the guideline also allows 60 minutes), and it does so every day. Quarter-hour settlement hangs on it, and dynamic tariffs under §41a EnWG are usually billed on this same series of register readings. For the time-variable grid charge under module 3, though, TAF 7 is only one of two routes; the other runs through TAF 2, and chapter 5 explains why. An intelligent metering system without TAF 7? An expensive digital meter.

TAF 3, 4 and 8 built tariffs on load thresholds, consumption volumes and power peaks. They have been missing from the guideline since version 1.1 of 2021⁷, and version 2.0 reassigns number 8, to load profile formation with maximum values, required from 2027⁵.

That leaves TAF 12, the prepaid tariff: a prepaid energy amount counts down, and at a threshold a signal goes out¹. It has nothing to do with feed-in management or redispatch. The current feed-in comes from TAF 9, and redispatch isn't a tariff use case at all; it's a process under §13a EnWG that runs through its own channels.

The prepaid case has been gone from the guideline since version 1.1 of 2021⁷. Version 2.0 doesn't bring it back⁵.

Grid: TAF 9 and TAF 10

Measurements from the low-voltage grid were something a distribution system operator never had. TAF 9 and TAF 10 provide them.

TAF 9 reports what a generation plant is feeding in right now, a PV system for instance. Billing has no use for the value; it's there for grid operation.

Without data like this a grid operator can't see which feeder is running up against its voltage limit right now. TAF 10 delivers it at the grid connection, namely voltage, current, active power, phase angle and frequency⁵, and one manufacturer calls the gateway with TAF 10 the most important sensor in the grid¹¹.

How often the data comes is for the Metering Point Operation Act, the MsbG, to decide.

For planning and analysis, quarter-hour values that arrive once a day are fine. You can't react to a bottleneck while it builds up with them; that's what minute values are for, and those cost extra and are capped at a quarter of the equipped connections.

So every grid operator has to pick the feeders it wants to see minute by minute. Blanket planning with minute-level TAF 10 simply isn't something the law foresees.

Then there is §14a. The Federal Network Agency allows grid-oriented control in principle only on the basis of a grid status assessment, and preventive control based on grid planning only as a transition until the end of 2028 at the latest¹³. Chapter 5 shows how tightly that ties measurement to control.

Control: why TAF 11 is not the route

"Control of interruptible consumption devices and generation plants" is how the catalogue describes TAF 11¹, and it would seem obvious to dim a heat pump under §14a through it. That is exactly what doesn't happen.

Back in 2021 the Higher Administrative Court of North Rhine-Westphalia set out the situation soberly. TAF 11, it said, was only optional even in the original guideline, missing from the "Basis" profile and implemented by none of the gateways on the market. For remote control, according to the BSI's own assessment, only the CLS proxy channel came into question³.

At the core nothing has changed, except that TAF 11 has vanished altogether: it hasn't been in the guideline since version 1.1 of September 2021, and version 2.0 doesn't name it either^7,5. Commands travel over the CLS channel, a secured channel the gateway brokers between an active external market participant in the WAN and a controllable device in the home network¹⁴. In the home network a control box sits at the end of it. It passes the command on to the device or to an energy management system.

The law sees it the same way. Section 34(1) no. 6 MsbG speaks of data communication "via the smart meter gateway and a control unit connected to it"¹², and a tariff use case doesn't appear in the provision at all.

Control in the gateway or in the box: two positions

Since 13 December 2024 a door has been open. Version 2.0 of the gateway protection profile, BSI-CC-PP-0073, comes with the functional package "Power Limitation" for the case where the gateway controls devices itself¹⁴. The control box would then be redundant. Whether it should be is what the BSI and the BDEW disagree about.

In August 2024 the BSI put out a discussion paper on control directly via the gateway. Integrated control was to be voluntary for manufacturers and the classic route via the control box would stay; with the integrated solution, though, the customer installation would need TR-03109-5 certification, because the box no longer acts as a tested counterpart¹⁵.

The BDEW, the German Association of Energy and Water Industries, pushed back in the consultation in September 2024 and reported on it on 4 October. Both routes should share one interface to the customer installation, and metering point operators shouldn't carry a double burden. The TR-03109-5 requirement for the integrated route should go: with it, the association warned, the solution would in effect never be implemented in the market because of the effort ("faktisch nicht umgesetzt"), and dropping it would not impair the security level¹⁵. Many metering point operators were building CLS management right then, it added, and that route stays necessary anyway for submetering and existing installations.

The discussion paper has since become an implementation note. On 16 September 2025, the same day as the note on TAF 5 and 16, the BSI published "Steuerung mit Nachweisführung im SMGW", control with verification in the gateway. In it the gateway uses EEBUS to limit consumption and feed-in of controllable devices and logs every instruction along with its acknowledgement. The note is not binding but is meant to move into TR-03109-1 later. On the point in dispute it says only: "Der TLS-Proxy ist im zu steuernden Produkt eine optionale Funktion. Ein Produkt mit implementiertem TLS-Proxy unterliegt dem Anwendungsbereich der [TR-03109-5]." The TLS proxy is optional in the controlled product, and a product that has one falls under TR-03109-5. The note names no certification duty for devices without a TLS proxy¹⁶.

A grid operator has shown that the technology works in a trial. In September and October 2025 Bayernwerk and Power Plus Communications sent around 1,100 control commands straight from the gateway to generation, storage and consumption devices, no control box involved, over EEBUS, and 99.63 percent went through¹⁷. At the time Bayernwerk expected certification at the manufacturers to start in early 2026 and control from the gateway to be widely usable from mid-2026¹⁷.

The BSI wants no untested counterpart in the home network, the BDEW no second certification route for the same goal. The BSI has since described the route inside the gateway technically, but it isn't binding, and as of mid-October 2026 no gateway is certified for it. That doesn't settle the dispute.

A sensible metering point operator therefore plans with the box and builds the architecture so it can be pulled out one day.

How new functions get into the device

Before a new tariff use case reaches a customer, the guideline has to be extended, the gateway recertified and the firmware in the field updated. Each of these steps takes time.

Testing happens twice along the way. A gateway needs a Common Criteria security certificate against protection profile PP-0073 and a second certificate against TR-03109-1 that confirms interoperability; the BSI list carries the two separately¹⁹. For the functions relevant to legal metrology, a PTB type-examination certificate is added³. Chapter 3 walks through the procedure.

First came the "Basis" profile with TAF 1, 2, 6 and 7. For TAF 14, an errata to the guideline followed in December 2019, which the court dates to the 12th and the BSI download page to the 16th^3,21. In early 2021 TAF 9 and 10 only existed in the optional "Netz" profile³ and became mandatory only with version 1.1 of September 2021⁷; they reached devices through recertification, at Power Plus Communications as early as 30 October 2020²².

Read somewhere today that TAF 9 and 10 are only arriving now? Then the source is at least five years old.

In the BSI's staged model⁴ the first stage includes, among other things, updating the metering system, communication with controllable devices via an active external market participant and the series of register readings (TAF 7), the second time-variable tariffs (TAF 2), grid status data (TAF 10), actual feed-in (TAF 9) and high-frequency readings (TAF 14).

New cases are on their way all the same. The BSI's implementation note of 16 September 2025 describes a planned extension with event-based tariffing in TAF 5 and event-based registration in a new TAF 16⁹, expressly as a note with "keinen verpflichtenden Charakter", no binding character⁹.

And the old state? Gateways under protection profile 1.3 and guideline 1.1 may still be installed until the end of 2027, while certifications under the new versions must show additional mandatory requirements from 1 January 2027⁶, TAF 8 and TAF 15 among them⁵.

What runs in the field, and what nobody measures

That the gateways support TAF 1, 2, 6, 7, 9, 10 and 14 is more than a manufacturer claim^22,1. Exactly these seven cases have been normative since version 1.1⁷, and all five gateways on the BSI list hold a conformity certificate against that version²⁴. Whether the functions are switched on in the field is another question, and no statistic answers it.

Between catalogue and reality, then, a gap remains. The catalogue describes what an intelligent metering system should be able to do; what it actually does in a particular grid sits in the gateway administrator's configuration, and nobody else sees that.

Four checks help close the gap in your own organisation:

1. Establish the certification status of your gateways

   For every device model in use, ask which versions of the protection profile and guideline it was last certified against. The BSI table doesn't show this, but the page for each certificate names the protection profile and the test basis²⁴.

2. Record the TAF configuration as an inventory

   Which tariff use cases run at which metering points, and since which firmware? Without that list, every statement about grid transparency is a guess, your own included.

3. Plan minute-level grid status data deliberately

   Treat the 25 percent from section 34 MsbG as a budget and spend it where grid calculation expects bottlenecks. Where gateways happen to be installed first is no criterion.

4. Specify control via CLS

   No TAF 11 in the specification.