Wallbox with power meter: Do I need a simple meter, MID or measurement and calibration law?

If you want to charge your electric car at home, it makes sense to buy a smart wallbox. This will make charging more convenient and significantly cheaper. But be careful, because not all wallboxes are the same. In addition to offering smart features, the right energy meter is crucial. This plays a role not only for companies, but also for you as a private individual.

Which type of energy meter your wallbox needs you are going to find out in this article.

There are three types of power meters for wallboxes

• Simple power meter

• MID-compliant meter

• Metering and calibration law-compliant meter (MessEG)

Note: The measurement and calibration law only applies to wallboxes installed in Germany.

A wallbox with a simple digital measurement of the charged kWh is often used in private households or by businesses charging exclusively company-owned cars.

This type of wallbox therefore makes sense if you only want to charge your electric car and control the power consumption of your wallbox. If you live and work in Austria, you may even be able to charge your company car at home and get paid for the electricity, unless your employer specifies otherwise.

In Germany, a wallbox with a simple energy meter for charging your company car is not permitted if electricity is to be billed or reimbursed.

Wallboxes with an integrated, simple power meter usually cost between €400 and €900. They are significantly less expensive than wallboxes with MID metres, as they do not offer calibrated measurement accuracy or certification of the meter and are therefore generally not suitable for the official billing of electricity costs.

MID stands for Measuring Instruments Directive and is an EU directive designed to guarantee a high level of measurement accuracy and transparency of measuring devices such as energy meters.

Wallboxes with MID-compliant meters are useful if you need legally compliant measurement and billing of charging currents whether for your employer, rental property or condominium, and are suitable for both single-user and, in some cases, shared wallbox use. Please note, however, that there may be differences from country to country.

Let’s have a look at Austria and Germany, starting with Austria.

If you are a tenant or owner in an apartment block and have your own car parking space with a wallbox that is connected to the general power supply and where only you charge, you will need a MID wallbox in Austria. The same applies if there are no dedicated parking spaces and several residential parties share wallboxes. In this case, an MID-compliant wallbox is essential so that the landlord or property management company can clearly allocate the charging current. 

If the wallbox were connected to your own flat meter, then a wallbox with a simple energy meter would be sufficient. This applies in both Austria and Germany.

An MID-compliant wallbox is basically necessary for Austria wherever you use it collectively and need legally compliant measurement and billing of the charging current. For example, when billing private vehicles and customers at company locations or hotels.

If you are an employee with a single-family home, you can charge your company car at home with a wallbox that has a simple meter and RFID function in Austria. This applies unless your employer requests otherwise and provided you are the only wallbox user.

If you live in a single-family home and share your wallbox for company car charging with others, such as, for example, your partner, a simple meter with RFID is currently sufficient in Austria, unless your employer requires a different option. In Germany, you need a wallbox that complies with measurement and calibration law.

Your employer may require you to charge your company car at home with an MID-compliant wallbox. Then you have no choice but to buy an MID wallbox.

In Germany, there are two cases in which an MID-compliant wallbox is absolutely necessary:

• Charging an electric car with a wallbox as a tenant in an apartment building: In Germany, an MID wallbox is mandatory if you are a tenant or flat owner in an apartment building and have your own car parking space. We are talking about the case when the wallbox is connected to the general power supply, and you are the only one using it.Thanks to MID, your landlord or the property management can clearly allocate the charging current to you. If the wallbox was connected to your own flat meter, a simple energy meter would be sufficient. This applies to both Germany and Austria.

• Charging a company car with a wallbox in a single-family home: If you own a single-family home and charge your electric company car at home with a wallbox used exclusively for this car, you will need an MID-compliant wallbox in Germany. This is necessary for your employer to reimburse the charging costs accurately.

Wallboxes with MID meters usually cost between €800 and €1200. As you can see, they are significantly more expensive than wallboxes with a simple meter, as they have to ensure legally compliant measurement and billing of the charging current and therefore also require MID certification.

Our go-e Charger PRO Cable, for example, is a wallbox with an MID meter and costs around €1150.

A wallbox that complies with measurement and calibration law is a wallbox with a MID-compliant meter. However, there are additional hardware and software requirements and rules so that consumption-based and proper billing can be guaranteed.

A wallbox that complies with measurement and calibration law usually costs between €1000 and €2000. Due to their greater complexity, measurement and calibration law-compliant wallboxes are therefore generally more expensive than wallboxes with MID or simple electricity meters.

Meters that comply with measurement and calibration law are mainly used in Germany in semi-public and public areas where high precision and traceability are required for billing. For example, in hotels, multi-storey car parks or at public charging stations. They are also used in company car parks, where not only the company's own vehicles, but also those of guests or customers, for example, can be charged at the wallboxes for a fee. So basically this is relevant for any situation where charging stations are shared and electricity metering and billing must be carried out correctly on a kWh basis. In Germany, this also applies to tenants and flat owners as well as company car owners who use their wallboxes collectively.

No, compared to Germany, you currently do not need a wallbox that complies with measurement and calibration law in Austria. At least it is not mandatory. Today, MID-compliant wallboxes are permitted in Austria for all of the aforementioned areas of application.